Table 2.

Coffee-associated changes of metabolic components and absorption via microbiota change.

Design	Treatment	Significance	Microbiota Change	Reference
In vivo rats	Coffee	Reduction in liver triglycerides	Clostridium Cluster XI ↓	Cowan et al. 2014 [85]
In vivo rats	Coffee	Reduction in obesity, metabolic syndrome, and inflammation; increase in gut barrier function	Firmicutes (F)-to-Bacteroidetes (B) ratio ↓	Cowan et al. 2014 [85]
In vivo rats	Coffee	Potential for gut dysbiosis, antibiotic resistance, opportunistic infection; may be involved with insulin resistance	Enterobacteriaceae ↑	Cowan et al. 2014 [85]
In vivo mice	Caffeine	Protection of gut lining, barrier function, and production of SCFAs	Dubosiella, Bifidobacterium and Desulfovibrio ↑	Chen et al. 2023 [86]
In vivo mice	Caffeine	Reduction in nutrient breakdown and immune modulation, but potentially, a restoration from dysbiosis	Bacteroides, Lactobacillus and Lactococcus ↓	Chen et al. 2023 [86]
In vivo mice	Coffee	Improvement in endotoxemia and systemic inflammation	Prevotella ↓	Nishitsuji, Watanabe, & Xiao 2018 [28]
In vivo mice	Coffee	Increase in gastrointestinal polypeptide; stimulation of insulin secretion and protection against metabolic syndrome	Coprococcus ↑	Nishitsuji, Watanabe, & Xiao 2018 [28]
In vivo humans In vivo mice	Coffee	Support in acetate production, but a marker of high-fat diet	Blautia ↓	Martinez et al. 2013 [87]; Nishitsuji, Watanabe, & Xiao 2018 [28]

Notes: ↑: Increased; ↓: Decreased.