Exploring tolerance and side effects of an innovative yeast-bound iron supplement: a feasibility trial

Abstract

Background

Iron deficiency is prevalent among female athletes, often leading to fatigue, impaired recovery, and decreased performance. Conventional oral iron supplements are associated with poor absorption and negative gastrointestinal side effects, resulting in low adherence. This feasibility trial investigated the tolerability and gastrointestinal effects of an iron-yeast complex (FeSC) supplement in physically active females to assess its potential for further study.

Methods

This single-arm, mixed-methods feasibility trial recruited 14 active females (18–25 years) who consumed FeSC-fortified cookies (40 mg elemental iron) every other day for 14 days. Gastrointestinal symptoms, stress, and recovery were assessed through daily and weekly questionnaires (daily questionnaires: Gastrointestinal Symptoms Questionnaire and Short Recovery and Stress Scale; weekly questionnaires: Patient-Reported Outcomes Measurement Information System (PROMIS) Gastrointestinal Symptom Scale; RESTQ Basic-24). Qualitative data on supplement acceptability were collected post-intervention. Feasibility was evaluated based on recruitment, retention, adherence, and safety criteria.

Results

Out of 52 participants who completed our screening questionnaire, 14 (age = 22 SD 2 years; weekly physical activity = 420 SD 140 min/week) met all criteria and completed the intervention. All feasibility criteria were met, including 100% retention, adherence, and questionnaire completion rates. Participants reported good supplement tolerability, with only a few cases of mild, transient gastrointestinal symptoms. A reduction in constipation symptoms compared to baseline and a reduction in diarrhea symptoms on days cookies were consumed compared to days they were not were observed. No serious adverse events occurred. While some participants noted a metallic aftertaste, 57% indicated that they would prefer the supplement in cookie form over traditional iron pills if given the choice.

Conclusions

This study demonstrates the feasibility and tolerability of FeSC supplementation in active females, with potential gastrointestinal benefits. Findings support progression to a larger trial assessing FeSC’s impact on iron status and long-term adherence.

Trial registration

ClinicalTrials.gov NCT06285851. Registered on January 30, 2024.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-025-01690-w.

Key messages regarding feasibility

• The primary uncertainty was the tolerability of an iron-yeast complex and the impact the supplement may have on gastrointestinal symptoms.

• The key findings of this research are that an iron-yeast complex in a fortified cookie is well tolerated and may even have beneficial gastrointestinal effects.

• The successful recruitment and adherence indicate that a larger trial assessing the long-term effects of iron-yeast complex on iron status is feasible. Future studies should include participants with suboptimal iron levels and refine the cookie formulation to improve taste.

Introduction

Iron deficiency (ID) is the most prevalent micronutrient deficiency globally and is responsible for over half of anemia cases worldwide [1]. Athletes are particularly susceptible to ID due to increased losses through sweat and reduced absorption secondary to exercise. Female athletes are at heightened risk compared to their male counterparts due to regular blood loss through menstruation. In athletes, ID can have detrimental effects on health and performance due to feelings of lethargy, poor recovery, and impaired energy availability [2].

The first-line treatment for ID is oral supplementation in the form of ferrous iron salts, such as ferrous fumarate, ferrous sulfate, and ferrous gluconate [3, 4]. However, the absorption rate of iron supplements tends to be poor, with the literature indicating a fractional iron absorption of 5–20%, depending on the dosing regimen [4]. Further, supplementation with oral iron is often accompanied by negative gastrointestinal side effects such as nausea, constipation, abdominal pain, and dark stools [5]. Such side effects generally lead to low compliance, and therefore efficacy, of oral iron supplementation [6–9]. While slow-release formulations tend to have improved tolerability over traditional formulations, the clinical efficacy of such products is limited [10].

Gut microbial composition contributes to the substantial gastrointestinal side effects associated with oral iron supplementation. Due to the low absorption of iron when consumed as an oral supplement, excess iron accumulates in the gastrointestinal tract, causing a shift in the taxonomy of the gut microbiota. This shift is characterized by a decrease in beneficial bacteria associated with gastrointestinal health such as Faecalibacterium and a concomitant increase in pathological bacteria associated with negative gastrointestinal effects such as Proteobacteria in those supplementing with oral iron [11, 12]. Complexing iron to nutritional yeast (Saccharomyces cerevisiae) provides an interesting vehicle for iron supplementation, as yeast offers a variety of health benefits to the host. Specifically, the gastrointestinal benefits of a yeast carrier may assist in offsetting the negative gastrointestinal effects of iron supplementation, including attenuating the pathological shift in the gut microbiota. Yeast is rich in ß-(1,3/1,6)-d-glucans (hereafter, ß-glucan), which have a variety of health-promoting effects [13–15], likely related to it being a soluble fibre, therefore exerting prebiotic effects [14]. At low doses (0.5–0.75 g/day), consumption of ß-glucan increases the health-promoting short-chain fatty acid-producing bacteria Bifidobacterium, Roseburia hominis, and Ruminococcus spp. in healthy participants [16, 17] and has beneficial health outcomes in a variety of gut-related ailments such as diarrhea, ulcerative colitis, and Crohn’s disease [18]. Such prebiotic effects of ß-glucans have the potential to nourish a beneficial gut microbiota and decrease negative side effects associated with iron supplementation. Further, complexing the iron to yeast may shift iron absorption from the small intestine to the colon. While the primary site of iron absorption is in the duodenum of the small intestine [19], the colon also contains divalent metal transporters (DMTs) in abundance [20, 21], suggesting the colon could be an additional site of iron absorption. Therefore, upon digestion of ß-glucans by microbiota, iron will be liberated resulting in a slower rate of release and a shift in the site of iron absorption compared to traditional iron supplements. However, no research is currently available, to our knowledge, to assess whether complexing iron with commercially available yeast (1) effectively increases iron status in humans and (2) impacts gastrointestinal side effects. Importantly, before assessing the effectiveness of such a supplement in a clinical population, it is essential to investigate whether a yeast-bound iron initiates fewer symptoms than traditional iron supplements to determine whether such a supplementation medium could be useful.

The primary aim of this study is to assess the feasibility and tolerability of an iron-enriched yeast (Saccharomyces cerevisiae) complex (FeSC) and evaluate any gastrointestinal effects that would typically be associated with iron supplementation, to elucidate whether a larger trial investigating the effectiveness of this iron-yeast complex in the treatment of ID is warranted. The secondary aim is to assess participant preferences for the supplement to inform whether taste and texture might impact participant retention in a longer-term study.

Materials and methods

Study design

This feasibility trial was retrospectively registered at ClinicalTrials.gov (NCT06285851; https://clinicaltrials.gov/study/NCT06285851?term=NCT06285851&rank=1) on January 30, 2024, and is reported according to the CONSORT statement for pilot and feasibility trials (Supplementary data 1). This study is a single-arm, mixed-methods design utilizing daily and weekly questionnaires, paired with a qualitative assessment of consumer preferences during a 14-day interventional period in which participants consumed the interventional product every other day (Fig. 1). The questionnaires were used to quantify gastrointestinal symptoms as well as feelings of stress and recovery. Open-ended qualitative data were collected following the 2-week intervention to gain insight into consumer preferences regarding the interventional product, further aiding the evaluation of the feasibility and potential acceptability of the interventional product. The study was approved by the Conjoint Health Research Ethics Board at the University of Calgary (REB23-0825) and the Mount Royal University Human Research Ethics Board (#103,708). All study participants provided written informed consent before being enrolled in the present study. The study complied with the protocols and good clinical practice guidelines of the International Conference on Harmonization and the Declaration of Helsinki.

Fig. 1.

Schematic representation of the study design. FeSc, yeast complexed iron 40 mg elemental iron/day; GISQ, Gastrointestinal Symptoms Questionnaire (22); PROMIS Gastrointestinal Survey, National Institutes of Health Patient-Reported Outcomes Measurement Information System Gastrointestinal Symptom Scale (24); RESTQ Basic, Recovery-Stress Questionnaire Basic-24 (19); SSRS, Short Recovery and Stress Scale (23)

Sample size

As the emphasis of the current study is to investigate feasibility and acceptability, a formal sample calculation was not implemented. The recruitment target for this research was 14 participants, based on recommendations that 12 participants per group is adequate for evaluating feasibility [22, 23] and accounting for a 10% attrition rate. After the recruitment target was reached, recruitment efforts were terminated.

Participants

Active females were recruited from Calgary, Alberta, Canada, using posters and snowball sampling to take part in this research. Inclusion criteria included being between the ages of 18 and 25 years, having a body mass index of < 25.0 kg/m², and engaging in moderate to vigorous activity for ≥ 240 min per week. Exclusion criteria included diagnosed chronic illness (including inflammatory bowel disease/irritable bowel syndrome), use of prescription medication (including hormonal birth control and antibiotics) in the past 3 months, current use of iron-containing supplements (including in a multivitamin), and allergies or intolerances to any of the supplement ingredients.

Investigational product

The investigational product used in this research was an iron-enriched yeast (Saccharomyces cerevisiae) complex (FeSC; commercially available as Lalmin® Fe10) produced by Lallemand Bio-Ingredients (Montreal, QC, Canada), where iron was complexed during biomass production of a proprietary primary grown yeast and then the yeast was pasteurized, leaving the yeast inactive. FeSC was then incorporated into a cookie by a commercial research kitchen (Prairie Research Kitchen, Winnipeg, MB) to mask the yeast flavor and allow for adequate iron dosing (per cookie: 120 kcal; 7 g fat; 13 g carbohydrate; 2 g protein). Each cookie contained 2 g of FeSC, delivering 20 mg of elemental iron. Participants were instructed to consume two cookies (delivering a total of 40 mg of iron) spread throughout the day every other day for 14 days. Alternate day dosing was chosen as the fractional absorption of iron has previously been shown to improve with every second day as compared to daily dosing [4]. A 2-week trial was chosen, as it was deemed long enough to challenge the compliance of the supplement and the burden to the participant, better informing the likelihood of compliance for a longer trial.

Questionnaires

Participants completed comprehensive surveys before beginning the supplement (day 0), at the midpoint of the intervention (day 7), and on the last day of supplementation (day 14). This included a modified National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) Gastrointestinal Symptom Scales [24], the RESTQ Recovery and Stress Effects (Basic-24; [19]), and additional free-form questions regarding symptoms not captured in the other surveys (Supplementaldata 2). In addition to these comprehensive questionnaires, participants completed daily questionnaires (days 1–13) consisting of the Gastrointestinal Symptoms Questionnaire (GISQ; [22]) and the Short Recovery and Stress Scale (SRSS; [23]). Participants were instructed to add insight into any symptoms experienced by indicating whether they thought symptoms were related to the supplement or something else (i.e., illness, menstrual cycle). Adherence to the supplement was assessed by participants reporting whether or not they consumed their cookies in each daily questionnaire. To gain insight into consumer preferences for the cookie supplement and further ascertain the tolerability of our investigational product, a final survey regarding cookie palatability and consumer perceptions was administered on day 14. All surveys were administered on the online Qualtrics platform (Seattle, USA). A schematic of the study timeline is depicted in Fig. 1.

Feasibility criteria

The feasibility of the supplement was evaluated based on criteria outlined by Thabane et al. [25]. The feasibility of using the cookies as a form of iron supplementation in a larger trial was assessed based on recruitment rates, retention rates, adherence to the supplement, and safety analyses, including the occurrence of serious adverse events (Table 1).

Table 1.

Overview of feasibility criteria and minimum standard necessary for progression to a larger trial during the feasibility study

	Assessment	Minimum standard necessary for progression	Achieved in feasibility trial	Feasibility criteria achieved?
Recruitment and eligibility	-Rate of recruitment -Reasons for exclusion -Reasons for non-participation	N/A  > 25% eligible and willing to participate	N = 52 27% (n = 14)	✓
Retention	The number of included participants retained/who managed to complete the study protocol	> 75% participants completed intervention and each survey	100%	✓
Adherence	Adherence to supplement protocol	> 80%	100%	✓
Participant preferences	Rating from 0 to 5 over 5 items; open feedback	50% of participants rating each category as at least “somewhat” favorable	An average of 12 participants rated each category as at least “somewhat” favorable (range 10–24)	✓
Safety analysis	Number of serious adverse events	No serious adverse events related to study	No serious events occurred	✓

✓ criteria achieved

Data analysis

Data were analyzed using GraphPad Prism (v. 10.0.0). Given the nature of the research as a feasibility trial, inferential statistics were not used. Rather, descriptive statistics with 95% confidence intervals are presented. Data from weekly questionnaires were used to compare symptoms from baseline, mid, and post-measurements, while data from daily questionnaires were used to compare symptoms on days cookies were consumed compared to days they were not to assess any negative effects in the upper gastrointestinal tract that might be associated with iron supplementation. End survey qualitative data were reported as participant impressions/comments. Data are presented as the median (range) unless otherwise stated.

Results

All participants (n = 14) completed the intervention (age = 22 SD 2 years; weight = 59.0 SD 7.4 kg; body mass index = 21.3 SD 2.1 kg/m²; reported physical activity = 420 SD 140 min/week). The supplement was well tolerated, and most participants indicated they would prefer the cookie over traditional iron supplementation in the form of capsules. In addition to no adverse events being reported throughout the study, the supplement appeared to have some beneficial health effects such as reductions in symptoms of constipation and diarrhea.

Feasibility criteria

All feasibility criteria were achieved in this trial. An overview of the assessed feasibility criteria is displayed in Table 1 and discussed below.

Recruitment and retention

Our online Consent to Contact form was completed by 52 participants between the date of opening (November 9, 2023) and when our target recruitment number (n = 14) was met (November 28, 2023). Reasons for exclusion are outlined in Fig. 2. Of the 14 participants who met inclusion criteria and consented to take part in the research, all participants completed the study in full (i.e., there was no participant attrition), leading to a retention rate of 100%.

Fig. 2.

CONSORT diagram of participant flow through the study

Questionnaire completion

A 100% completion rate was observed for all participants, leading to a complete data set for daily, weekly, and additional end survey questionnaires.

Adherence to the intervention

All participants reported a 100% compliance rate, consuming two cookies every other day for 14 days for a total of 14 cookies consumed.

Acceptability of the supplement

Participants reported tolerating the cookies well, with the chief complaint being a metallic aftertaste. Given the choice of consuming an iron supplement in the cookie or pill form, 43% (n = 6) responded that they would prefer a pill format while 57% (n = 8) would rather consume iron in the cookie format.

Safety

No serious adverse events were reported throughout the study. Three participants reported effects that they thought might have been related to the supplement that were not captured by the gastrointestinal questionnaires. One participant reported a mildly increased frequency of bowel movements, and another reported feeling slightly nauseous after consuming cookies on 1 day but that the nausea subsided after an hour or so and did not reoccur. No participant reported continuing symptoms throughout the day. Quantification of gastrointestinal symptoms is outlined below.

Daily questionnaire

A reduction in diarrhea symptoms was observed on days participants consumed the cookies compared to days they did not (Fig. 3; Table 2). Some participants also noted the incidence of dark/tarry stools on days they consumed the supplement. No other notable differences between days cookies were consumed and days they were not were found. There were no differences in markers of stress and recovery between days on which cookies were consumed or not (Table 2).

Fig. 3.

Participant reports of constipation (A) and diarrhea (B). Mean and individual data shown for each. Constipation was assessed weekly using the National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) [24] which quantifies both frequency and severity of symptoms; diarrhea was assed daily using the Gastrointestinal Symptom Scales [26] where 1 = symptom not present, 2 = symptom present and minimal, 3 = symptom present and mild, 4 = symptom present and somewhat moderate, 5 = symptom present and moderate, 6 = symptom present and somewhat severe, and 7 = symptom present and severe. CD cookie consumption days, NCD non-consumption days. Error bars represent means ± SD

Table 2.

Health, stress, and recovery metrics gathered using daily questionnaires

Measures	NCD	CD	NCD-CD mean difference 95% CI
Health indices
Overall health quality	2 (1–3)	2 (1–3)	− 0.13, 0.05
Overall health vs normal day	3 (2–4)	3 (3–4)	− 0.18, 0.08
Nausea or vomiting	1 (1–2)	1 (1–1)	− 0.19, 0.29
Heartburn	1 (1–2)	1 (1–2)	− 0.03, 0.03
Abdominal discomfort	1 (1–3)	1 (1–2)	− 0.32, 0.21
Headache	1 (1–2)	1 (1–2)	− 0.07, 0.37
Fatigue	2 (1–3)	2 (1–4)	− 0.31, 0.13
Diarrhea	2 (1–3)	1 (1–2)	0.21, 1.23
Constipation	1 (1–3)	1 (1–2)	− 0.13, 0.33
Number of bowel movements	2 (1–5)	2 (1–4)	− 0.33, 0.05
Number of black/tarry bowel movements	0 (0–0)	0 (0–1)	− 0.13, 0.01
Stress and recovery indices
Physical performance capability	4 (3–6)	4 (3–6)	− 0.39, 0.30
Mental performance capability	4 (3–6)	3 (3–6)	− 0.38, 0.42
Emotional balance	4 (3–6)	4 (3–6)	− 0.38, 0.32
Overall recovery	4 (3–6)	4 (3–6)	− 0.22, 0.35

Symptoms and health measures were assessed using the Gastrointestinal Symptoms Questionnaire [26] where 1 = symptom not present, 2 = symptom present and minimal, 3 = symptom present and mild, 4 = symptom present and somewhat moderate, 5 = symptom present and moderate, 6 = symptom present and somewhat severe, and 7 = symptom present and severe; stress and recovery measures were assessed using the Short Recovery and Stress Scale [27]; symptoms were rated as 1 = does not apply to 6 = fully applies. Data are presented as median (range)

CD Cookie consumption days, NCD Non-consumption days, CI Confidence interval

Weekly questionnaires

A reduction in constipation symptoms was observed from baseline to post-intervention (Fig. 3). Additionally, diarrhea symptoms were reduced from baseline to day 7 but then returned to baseline levels at day 14 with supplement consumption (Table 3; Fig. 3). No effect on recovery was observed over the intervention, though a trend for decreased stress was noted throughout the intervention (Table 3).

Table 3.

Health, stress, and recovery metrics gathered using weekly questionnaires

Symptoms	Baseline	Mid	Post
Health indices
Constipation	4 (1–14) 2.87–7.70	2 (0–21) 1.13–7.87	2 (0–11) 1.09, 5.19
Belly pain	2 (0–10) 1.25–5.47	4 (0–8) 1.71–5.15	4 (0–10) 2.14, 6.00
Diarrhea	3 (0–11) 1.37–6.63	1 (0–5) 0.60–2.83	3 (0–9) 1.58, 5.28
Bloating	12 (2–30) 6.81–17.3	8 (1–24) 5.20–14.08	9 (1–26) 5.31, 14.97
Nausea	2 (0–6) 1.02–3.27	2 (0–6) 0.72–2.85	1 (0–8) 0.33, 3.1
Gastroesophageal reflux	3 (1–21) 1.86–9.0	2 (0–15) 1.22–6.35	2 (0–12) 1.32, 6.40
Stress and recovery
Overall recovery	43.3 (1.7) [34.3, 52.7]	42.7 (1.4) [33.9, 43.8]	44.1 (1.6) [31.6, 43.5]
Overall stress	43.5 (4.3) [39.6, 47.1]	38.9 (2.3) [39.8, 45.7]	37.6 (2.3) [40.6, 47.6]

Health data were assessed using a modified National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) Gastrointestinal Symptom Scale [24], which quantifies both frequency and severity of symptoms; stress and recovery data were assessed using the RESTQ-Basic [28]; a higher score for health indices indicates more symptoms were experienced; lower stress and recovery scores indicate reduced stress levels; health data arepresented as median (range) 95% confidence intervals; stress and recovery scores are presented as mean (SE) [95% confidence intervals]

Discussion

This study investigated the feasibility of an iron-complexed yeast (FeSC) as a strategy to supplement iron while mitigating adverse gastrointestinal side effects. Results suggest that supplementation with FeSC is viable in active females and may have favorable gastrointestinal effects, such as improvements in symptoms of diarrhea and constipation. All of our pre-defined feasibility criteria were achieved in this trial. Overall, high responsiveness to recruitment materials, retention, and study adherence was attained.

Given the achievement of all of our pre-defined feasibility criteria and favorable gastrointestinal reports during a 14-day intervention involving the consumption of cookies fortified with FeSC, interventions assessing the effect of the supplement on iron status in active females are warranted. However, a chief complaint of participants was supplement flavor, so revisiting the supplement formula to improve participant perceptions and improve compliance over a longer trial may be warranted. Importantly, desirable taste must be carefully considered when delivering iron in a cookie-based format to limit the risk of overconsumption, which could lead to health implications related to too much iron. Recruitment based on demographic information such as physical activity levels and anthropometry was successful, with target recruitment reached in 19 days. This suggests recruitment from this population is reasonable. Further, participant burden was deemed acceptable, and there were no concerns with completion of the questionnaires, despite a daily and weekly frequency. Future research investigating the role of our supplement in active females can use similar comprehensive questionnaires to gain insight into the gastrointestinal effects of FeSC.

In addition to all feasibility criteria being achieved, short-term supplementation with FeSC resulted in generally positive effects on gastrointestinal health. While iron supplementation is usually associated with an increased incidence of constipation [29], the results of the current research found a reduction in constipation symptoms from pre- to post-intervention and reduced reports of diarrhea on days cookies were consumed compared to days they were not. Though scores for both constipation and diarrhea reported at all timepoints are similar to what would be expected in the general population [24, 26], improvements despite oral iron supplementation suggest potential benefits on even subclinical indices of constipation and diarrhea. Such effects may be due to the prebiotic properties of the nutritional yeast in the supplement, as it is high in fiber and contains beneficial bioactive ß−1,4-mannan oligosaccharides and ß−1,3/1,6-d-glucans [14, 15]. Some participants (n = 4) reported black or tarry stools with supplement consumption, though this is to be expected with iron supplementation [30]. No participant reported concern or dropped out due to experiencing darkened stools. Future trials involving the supplement should inform participants that dark or tarry stools may be expected with consumption of the supplement.

End-survey data capturing participant preferences for the supplement indicated that study participants tolerated the supplement very well, with the biggest concern being supplement flavor and aftertaste. Regardless, 8 of 14 participants would choose the supplement over a traditional iron pill. The formulation of the cookie may be revisited to improve the flavor and aftertaste to improve participant perceptions and increase the likelihood of adherence over a longer trial.

Strengths and limitations

Despite potential concerns about implementing a dietary intervention in active females, including hesitancy to alter their diet or concerns over energy intake, we were able to achieve a modest recruitment rate in a relatively short amount of time, indicating that recruitment of this demographic should not be a limiting factor in a larger trial. However, the possibility that a more comprehensive trial, including multiple lab visits and biological sample collection, could increase the participant burden and lead to reduced recruitment rates cannot be ignored. Participant history of iron supplementation was not captured in the current study, so it is possible that participants had not supplemented with iron previously, and thus did not have a good understanding of the side effects associated with oral iron supplementation. Future research should compare FeSC to traditional iron supplements to compare gastrointestinal effects. Further, to achieve meaningful results with iron supplementation, individuals with suboptimal iron status should be recruited for future research. Adding baseline iron status as an inclusionary criterion would be desirable for the study of iron deficiency alleviation, but may also increase the challenge in recruiting participants. Future research should also aim to compare the effectiveness of FeSC in reducing symptoms in recreationally active individuals (such as in the current study) compared to athletes with a more demanding training schedule. A larger study should also consider dietary intake to describe enhancers or inhibitors of iron and consider pre- or probiotic intake as a confounder to any results.

Conclusion and implications

This study showed that supplementation with a cookie fortified with FeSC not only was feasible but may have favorable effects on the gastrointestinal symptoms in physically active females. Supplement flavor and aftertaste were noted as concerns by participants, so the formulation of the supplement may be revisited to improve the taste and, hopefully, improve retention rates over a longer study duration. This feasibility study provides valuable information on the design and implementation of future studies investigating the effect of FeSC on iron status and gastrointestinal health in active females.

Abbreviations

DMT

Divalent metal transporter

FeSC

Iron-yeast complex

GISQ

Gastrointestinal Symptoms Questionnaire

ID

Iron deficiency

PROMIS

Patient-Reported Outcomes Measurement Information System

RESTQ

Recovery and stress questionnaire

SRSS

Short Recovery and Stress Scale

Authors’ contributions

Conceptualization: JS, TAT, and JAP; methodology: JS, TAT, and JAP; formal analysis: KAS, BAD, and JS; funding acquisition: MJM, JS, KAS, and RAR; investigation: BAD and GM; project administration: BAD, GM, and JS; supervision: JS; visualization: KAS and JS; resources: TAT; writing—original draft: KAS; writing—review and editing: KAS, TAT, BAD, GM, JAP, MJM, RAR, and JS. All authors read and approved the final manuscript.

Funding

Funding for this work was provided by NSERC-Alliance in partnership with Lallemand Bio-Ingredients (Grant # ALLRP/586408–2023).

NSERC,ALLRP/586408-2023,Jane Shearer.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

All participants provided written, informed consent prior to engaging in any research-related activities. This research was approved by the Conjoint Health Research Ethics Board at the University of Calgary (REB23-0825) and the Mount Royal University Human Research Ethics Board (#103708).

Consent for publication

Not applicable.

Competing interests

TAT is an employee of Lallemand Bio-Ingredients, a company manufacturing and marketing yeast-based ingredients. All other authors declare that the research was conducted without commercial or financial relationships and thus declare no conflict of interest.