Final answer:
Gut microbes are significantly involved in metabolic functions, immunomodulation, and trophic effects on the gut mucosa and gut-brain axis, contributing to the overall well-being of the host.
Step-by-step explanation:
The three major processes that gut microbes are involved in include: metabolic functions, immunomodulatory roles, and trophic actions. First, gut microbes play a crucial role in metabolism by fermenting undigested carbohydrates and producing short-chain fatty acids that serve as key sources of energy; they also synthesize essential vitamins like vitamin B12, folate, riboflavin, and vitamin K. Secondly, in terms of immunomodulation, the microbiome produces anti-inflammatory factors and antioxidants, and prevents the attachment of harmful bacteria that may cause chronic diseases, hence regulating the immune system. Lastly, gut microbes have trophic effects by maintaining the integrity of the gut mucosa and affecting the gut-brain axis, which is important for overall health and even mood regulation.