Impact of protein on the composition and metabolism of the human gut microbiota and health

Abstract

The composition and metabolic activity of the bacteria that inhabit the large intestine can have a major impact on health. Despite considerable inter-individual variation across bacterial species, the dominant phyla are generally highly conserved. There are several exogenous and gut environmental factors that play a role in modulating the composition and activities of colonic bacteria including diet with intakes of different macronutrients, including protein, accounting for approximately 20% of the microbial variation. Certain bacterial species tend to be considered as generalists and can metabolise a broad range of substrates, including both carbohydrate- and protein-derived substrates, whilst other species are specialists with a rather limited metabolic capacity. Metabolism of peptides and amino acids by gut bacteria can result in the formation of a wide range of metabolites several of which are considered deleterious to health including nitrosamines, heterocyclic amines and hydrogen sulphide as some of these products are genotoxic and have been linked to colonic disease. Beneficial metabolites however include SCFA and certain species can use amino acids to form butyrate which is the major energy source for colonocytes. The impact on health may however depend on the source of these products. In this review, we consider the impact of diet, particularly protein diets, on modulating the composition of the gut microbiota and likely health consequences and the potential impact of climate change and food security.

Dysbiotic change in gastric microbiome and its functional implication in gastric carcinogenesis

“…Cysteine and methionine, which are sulfur-containing amino acids, are important for cancer cell growth and metabolism 50 , 51 . Hydrogen sulfide can be formed by bacteria using these sulfur-containing amino acids, which can inhibit butyrate metabolism, consequently leading to mucosal damage and inflammation of the intestinal tract 52 . In colorectal cancer, microbe-derived hydrogen sulfide seems to play a role in cancer progression and colon health 53 .…”

Effects of low protein diet with a balanced amino acid pattern on growth performance, meat quality and cecal microflora of finishing pigs

“…At the genus level, we also found that the LP and VLP diets increased the relative abundances of Turicibacter , Terrisporobacter , Clostridium_sensu_stricto_1 and UCG‐005 , and decreased the relative abundances of Lactobacillus and Streptococcus . Terrisporobacter , Clostridium_sensu_stricto_1 and UCG‐005 were reported as fiber‐degrading bacteria, 43–45 whereas Lactobacillus and Streptococcus are capable of producing amines through decarboxylation of amino acids 46–48 . This can also be generated in meat and associated with microbial activity in meat 49 .…”

Role of Food Antioxidants in Modulating Gut Microbial Communities: Novel Understandings in Intestinal Oxidative Stress Damage and Their Impact on Host Health

“…The diet habits exert a significant impact on the microbiota composition. For instance, the consumption of plant-based protein enhances the composition of Enterococcus, Bifidobacterium, and Lactobacillus while it decreased the composition of Escherichia coli, Bacteroides, and Clostridium perfringens [33,34]. In addition, the consumption of plantbased protein enhanced the production of short chain fatty acids which in turn exerts anti-inflammatory effect during obesity and help in maintaining the mucosal barrier [35].…”