TABLE 2.

Observational studies investigating the effects of fermented food consumption on human health.

Diet and fermented food matrix	Brief diet description	Study design	Control group	Participants	Participant characteristics	Gut microbiome analysis method	Variation in gut microbiome detected	Health outcome targeted	Health outcome achieved	Reference
Lacto‐fermented vegetables	Balanced diet including a 2‐year‐long daily consumption of lacto‐fermented vegetables	Cohort, comparison of consumer groups versus non‐consumers	Non‐consumers	47	Male (29.79%), adults (20–50 years), normal‐weight	16S rRNA and ITS2	Bacteria: ↑ Leuconostoc mesenteroides, Parabacteroides distasonis, Lachnospira, Ruminococcaceae, Coproccocus, Blautia, Clostridiales, Coprobacillus, Alphaproteobacteria Fungi: ↑ Rhodotorula mucilaginosa, Penicillium, Starmerella, Cryptococcus laurentii and Vishniacozyma carnescens	None	‐	Guse et al. (2023)
Dairy products	Balanced diet including cheese, yogurt and dairy milk among fermented foods high‐intake	Cohort, comparison of groups with high versus low intake of FFs	Plant‐based diet	37	Male (56.76%), children (2–3 years), normal‐weight	16S rRNA	↑ Streptococcus salivarius subsp. thermophilus, Erysipelatoclostridium ramosum, Lachnoclostridium ↓ Faecalibacterium prausnitzii, Fusicatenibacter, Alistipes, Bacteroides, Parabacteroides	None	‐	Smith‐Brown et al. (2016)
Dairy products	Balanced diets including yogurt, natural yogurt, sweetened yogurt, cheese, matured/semi‐matured cheese, fresh cheese, fermented milk	Cross‐sectional, comparison of consumer groups versus non‐consumers	Non‐consumers	130	Male (29.23%), adults (58.18 ± 17.10 years), normal‐weight and overweight	qPCR	↑ Akkermansia muciniphila ↓ Bacteroides	Cardiometabolic Disease and metabolic syndrome	Yes	González et al. (2019)
Fermented milk	Balanced with a fermented milk high‐intake	Case–control, comparison of groups affected by ASD versus not affected	Children not affected by ASD	46	Male (100%), children (4–9 years), normal‐weight and obese	16S rRNA	↑ Clostridia, Lactobacillus, Blautia, Anaerostipes and Fusicatenibacter	Autism spectrum disorder (ASD)	Yes	Tomova et al. (2020)
Fermented products	Diet including yogurt, wine, sauerkraut, pickled vegetables, kombucha, kimchi and beer, aside from fermented plants	Cohort, comparison of consumer groups versus non‐consumers	Non‐consumers	115	Male (52.60%), adults (19–70 years), normal‐weight	16S rRNA	↑ Bacteroides, Pseudomonas, Dorea, Lachnospiraceae, Prevotella, Alistipes putredinis, Oscillospira, Enterobacteriaceae, Fusobacterium, Actinomyces, Achromobacter, Clostridium clostridioforme, Faecalibacterium prausnitzii, Bacteroides uniformis, Clostridiales and Delftia	None	‐	Taylor et al. (2020)
Yogurt and Probiotic Fermented Milk (PFM)	Not available	Cohort, comparison of consumer groups versus non‐consumers	Non‐consumers	272	Male (49.26%), adults (25–50 years), normal‐weight and overweight	16S rRNA	↑ Bifidobacterium	None	‐	Redondo‐Useros et al. (2019)
Asian and African diet	Lacto‐vegetarian diet	Cross‐sectional, comparison between Asian versus African diet	Control‐based Asian/African	100	Male (0%), adults (16–35 years), normal‐weight	16S rRNA	↑ Bifidobacterium, Succinivibrio and Escherichia‐Shigella in Asian population ↑ Ruminococcus, Lachnospiraceae, Succinivibrio and Faecalibacterium in African population	None	‐	Tang et al. (2019)
Kazakh nomads diet	High‐fat, high‐meat and low‐vegetable diet	Cross‐sectional, comparison among interindividual variations	Control‐based interindividual variations	29	Male (37.93%), adults (6–84 years), normal‐weight and overweight	16S rRNA	↑ Bifidobacterium and Collinsella aerofaciens	None	‐	Li et al. (2019)
Rural Saudi Arabian diet	Diet characterised by six plant‐based fermented foods, called Lohoh in the local language	Cross‐sectional, comparison between rural versus urban Arabian diet	Urban Saudi Arabian diet	28	Male (92.86%), adults (>18 years), weight not reported	16S rRNA	↑ Verrucomicrobaeota, Acetobacter, Mycoplasma, Treponema berlinense and Treponema succinifaciens	None	‐	Angelakis et al. (2016)
Sakura diet	Not available	Cohort, comparison among interindividual and intraindividual variations	Control‐based interindividual and intraindividual variations	10	Male (50.00%), adults (men, 37.2 years; women, 38.2 years) normal‐weight	16S rRNA	↑ Bifidobacterium	None	‐	Hisada et al. (2015)