Plant proteins and gut health: Understanding the impact on microbiota and human health

Plant proteins are gaining recognition not only for their nutritional value but also for their influence on gut microbiota and associated health outcomes. Due to their compact structure, lower digestibility, and distinct amino acid profiles, a greater proportion of these proteins reaches the colon, where they undergo microbial fermentation. Microbial fermentation of these proteins produces various metabolites, including beneficial compounds such as short-chain fatty acids and potentially harmful byproducts such as ammonia, hydrogen sulfide, and indolic compounds. The extent and nature of these metabolites depend on the type, composition, structure, and digestibility of the proteins consumed. Therefore, this chapter examines the effects of various plant protein sources on gut microbial composition and metabolite production. It also examines current evidence from both human and animal studies regarding the role of plant protein intake in metabolic and gastrointestinal disorders, including obesity, type 2 diabetes, inflammatory bowel disease, and colorectal cancer. In addition, the chapter covers foundational aspects such as gut microbial composition, distribution, and the range of gut-derived metabolites.