Table 20.
Summary of THY's effects on gut microbiota across animal models.
| Animal model | Supplement composition | Dosage/duration | Main findings on microbiota | References | Year |
|---|---|---|---|---|---|
| Dogs | Yeast cell wall + OEO | 1.5 and 3 kg/ton for 20 days | Increases Blautia spp. and Fecal ibacterium spp., decreases Streptococcus spp. in feces; greater bacterial diversity | (17) | 2023 |
| Weaned piglets | EOs blend (18% THY + CIN) | 0.01% for 35 days | Improves fecal scores; reduces E. coli in cecum, colon, rectum; increases Lactobacilli-E. coli ratio | (18) | 2012 |
| Encapsulated EOs (THY + CIN) | 0, 50, 100, or 150 g/T of feed | Decreases E. coli counts in feces | (149) | ||
| THY | 0.0067% or 0.0201% for 7 days | No significant effect on cecal anaerobes | (168) | ||
| THY + BA | THY: 100–200 mg/kg + BA: 1,000–2,000 mg/kg) for 14 days | Higher Lactobacillus spp. in ileum and Bacillus spp. in caecum | (133) | 2015 | |
| THY-CAR blend (1:1 ratio) | 100 mg/kg for 14 days | Decreases Enterococcus spp. and E. coli; increases Lactobacillus spp. | (15) | 2017 | |
| Lippia origanoides-E. caryophyllata EOs (47.5% THY) | 67 mg/kg; blends up to 100 mg/kg | No effect on Enterobacteria or Lactobacillus spp. | (20) | 2021 | |
| EOs blend (10% THY) | 0–400 mg/kg for 42 days | No effect on microbiota in intestinal segments | (123) | 2023 | |
| Goats | THY | 600 mg/L | Alters bacterial community | (173) | 2020 |
| Blue foxes | THY | 0, 100, 200, and 300 mg/kg for 30 days | THY increases the abundance of Bifidobacterium spp., Fusobacterium spp., and Allobaculum spp. in the gut | (150) | 2024 |
| Fattening rabbits | THY supplementation | Not specified | Higher Lactobacillus spp. and Bifidobacterium spp. populations | (16) | 2021 |
| Broiler chickens | THEO | Not specified | Reduction in pathogenic bacteria, promotion of beneficial microbes | (70) | 2019 |
| THEO | 0.5% and 1% for 42 days | Decreases microbial population in cecal content | (164) | 2019 | |
| Microencapsulated THY + fumaric acid | 0.6 g/kg for 21 days | Increases Bacteroidetes, Bacillaceae, and Rikenellaceae; decreases Pseudomonadaceae in cecal content | (170) | 2021 | |
| Ducks | EOs blend (13.5% THY and 4.5% CIN) | 11–42 days | Reduces cecal coliforms, total aerobes, and lactose-negative Enterobacteria | (142) | 2019 |
| Quail | THEO (35.4% THY) | Different levels | Lower coliforms in supplemented groups compared to antibiotic group; Lactobacilli unaffected | (80) | 2019 |
| Turkey | THY or EOs blend with THY | 30 mg/kg for 56 days | Increase lactic acid bacteria, decreased coliforms in caecum; no effects in ileum | (127) | 2014 |
| Rainbow trout | Phytogenic additive (6 g/kg THY) | 1 g/kg for 8 weeks | Lower anaerobe and Lactobacillus counts | (114) | 2012 |