Table 1.
Specifications of selected studies evaluating the efficacy of probiotic/synbiotic treatment in dogs with CIE.
| Reference | Inclusion Diagnosis | Experimental Setting * | Probiotic Strain(s)/Treatment | Probiotic Dosage | Time § | Main Outcomes |
|---|---|---|---|---|---|---|
| Sauter et al. (2005) [206] |
CIE | Ex vivo study | L. acidophilus NCC 2628, L. acidophilus NCC 2766, L. johnsonii NCC 2767 | 1 × 107 CFU/mL of medium | 36 h | Increased IL-10 mRNA and protein expression; decreased ratio of TNF-α/IL-10, IFN-γ/IL-10 and IL-12p40/IL-10 mRNA levels. |
| Schmitz et al. (2014) [207] |
FRE | Ex vivo study | E. faecium NCIMB 10415 | 1 × 107 CFU/mL of medium | 5 h | Increased TNF-α protein expression from whole blood in both groups. TNF-α protein responses opposite in blood and biopsies. |
| Schmitz et al. (2015b) [208] |
CIE | Ex vivo study | E. faecium NCIMB 10415 | 1 × 107 CFU/mL of medium | 5 h | No effect on NLRP3, casp-1, IL-1β and IL-18 gene and protein expression. |
| FRE | In vivo placebo-controlled randomised trial | E. faecium NCIMB 10415 + FOSs + gum Arabic + hydrolysed protein diet | 1 × 109 CFU/dog/day | 42 days | ||
| Sauter et al. (2006) [209] |
FRE | In vivo placebo-controlled randomised trial | L. acidophilus NCC 2628, L. acidophilus NCC 2766, L. johnsonii NCC 2767 + novel protein diet | 1 × 1010 CFU/dog/day (of each strain) |
28 days | Decreased duodenal IL-10 and increased colonic IFN-γ mRNA expression; † increased numbers of Lactobacillus spp.; † detection of L. johnsonii NCC 2767 in 5 of 8 dogs after probiotic supplementation; no significant differences in clinical response between groups. |
| Schmitz et al. (2015a) [210] |
FRE | In vivo placebo-controlled randomised trial | E. faecium NCIMB 10415 + FOSs + gum Arabic + hydrolysed protein diet | 1 × 109 CFU/dog/day | 42 days | No significant differences in clinical efficacy and histology score between groups. No effect on TLR-2, -4, -5, -9; IL-17A; IL-22; IL-23p19; RORC; IL-2; IL-12p35; TNF-α; IL-4; IFN-γ; IL-10; TGF β; IL-1β; IL-18; NLRP3; casp-1; TFF1; TFF3 and PPAR-γ mRNA expression. |
| Pilla et al. (2019) [211] |
FRE | In vivo placebo-controlled randomised trial | E. faecium NCIMB 10415 + FOSs + gum Arabic + hydrolysed protein diet | 1 × 109 CFU/dog/day | 42 days | Small increase in faecal species diversity; no significant differences in microbial community composition between groups. |
| Westermarck et al. (2005) [8] |
ARE | In vivo uncontrolled study | L. rhamnosus ATCC 53103 | 1 × 1010 CFU/dog/day | ≤30 days | Failure to avoid recurrence of diarrhoea in 9 of 9 dogs. |
| Isidori et al. (2021) [162] |
ARE + IRE | In vivo uncontrolled study | B. subtilis DSM 15544 | 125 × 109 CFU/10 kg BW/day | 30 days | No significant differences in clinical outcome between pre- and post-treatment. Increased faecal concentrations of butyric acid. † |
| Rossi et al. (2014) [212] |
IRE | In vivo comparative randomised trial | L. plantarum DSM 24730, S. thermophiles DSM 24731, B. breve DSM 24732, L. paracasei DSM 24733, L. delbrueckii subsp. bulgaricus DSM 24734, L. acidophilus DSM 24735, B. longum DSM 24736, B. infantis DSM 24737 | 112–225 × 109 CFU/10 kg BW/day | 60 days | Decreased clinical and histological scores and reduced proinflammatory CD3+ T-cell infiltration in both study groups; increased FoxP3+ immunosuppressive cells and relative abundance of genus Faecalibacterium. |
| White et al. (2017) [213] |
IRE | In vivo placebo-controlled randomised trial | L. plantarum DSM 24730, S. thermophiles DSM 24731, B. breve DSM 24732, L. paracasei DSM 24733, L. delbrueckii subsp. bulgaricus DSM 24734, L. acidophilus DSM 24735, B. longum DSM 24736, B. infantis DSM 24737 + prednisone + elimination diet | 112–225 × 109 CFU/10 kg BW/day | 56 days | Increased E-cadherin, occludin and zonulin protein expression. |
| D’Angelo et al. (2018) [214] |
IRE | In vivo placebo-controlled nonrandomised trial | S. boulardii + dietary therapy + antibiotics + steroids ± immunosuppressors | 1 × 109 CFU/kg BW/twice a day | 60 days | Lower clinical activity index, stool frequency, stool consistency; higher body condition score. |
§ Incubation time lapse for ex vivo studies; † tendency (0.05 < p ≤ 0.1); ARE = antibiotic-responsive enteropathy; BW = body weight; CIE = chronic inflammatory enteropathy; CFU = colony-forming units; FOSs = fructooligosaccharides; FRE = food-responsive enteropathy; IRE = immunosuppressive-responsive enteropathy. * Ex vivo studies were performed on freshly retrieved duodenal explants from dogs with CIE. Group divisions per reference: [206]: healthy dogs vs. dogs with CIE evaluated before and after exposure to lactobacilli; [207]: healthy dogs vs. dogs with FRE evaluated before and after E. faecium exposure; [208]: healthy dogs vs. dogs with CIE, with CIE group receiving hypoallergenic diet either alone or in combination with the symbiotic product.