Gut bacteria are an important part of our microbiota ecosystem in the human gut, which is colonized by 1,014 microbes, ten times more than the human cells!
Gut bacteria play an important role in our health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function.
However, they can also be potentially harmful due to the change of their composition when the gut undergoes changes due to the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle.
Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and even autism.
Immunoregulatory (The control of immune responses between lymphocytes and macrophages) activity is the main function of gut bacteria in the pathogenesis of diseases. Diet-induced dysbiosis affects disease susceptibility, including IBD, diabetes, and obesity.
In recent years, prebiotics and probiotics have been widely used in the treatment of some diseases, and have shown great effects.
The gut resists bacteria through two barriers, the mechanical barrier and the immune barrier.
The mechanical barrier consists of a single layer of polarized intestinal epithelial cells, the enterocytes and mucus.
Commensal bacteria (act on our immune system to induce protective responses that prevent colonization and invasion by pathogens). Commensal bacteria and probiotics can promote the integrity of gut barriers.
Commensal bacteria contribute to our gut defense system mainly by resisting the invasion of bacteria and helping our body’s immune system. The invasion of bacteria is also prevented by commensal bacteria due to the reduction of the intestinal pH by the production of lactate and short-chain fatty acids.
Gut bacteria maintain resistance against the colonization of bacteria by competing for your nutrients and attaching to sites on the mucosal surface in the colon, a phenomenon collectively known as “colonization resistance”. Whereby the intestinal microbiota protects itself against incursion by new and often harmful microorganisms. Colonization resistance was first identified in 1967, and it was initially referred to as antibiotic associated susceptibility.
In the past, regular consumption of fermented foods helped to maintain healthy gut flora, but these foods are increasingly rare in our diet. The combination of unhealthy lifestyles and a lack of fermented foods in the diet makes it important for most people to supplement with probiotics.
Probiotics promote a healthy balance of gut bacteria and have been linked to a wide range of health benefits.
Probiotics are naturally-occurring friendly bacteria that enhance health in several key ways, including:
- Assisting with digestion and nutrient assimilation
- Helping inhibit the overgrowth of harmful bacteria
- Supporting the immune system
- Maintaining bowel health and assisting with proper elimination
- Helping restore and maintain balanced flora after antibiotics, which kill the beneficial gut flora
Zhang, Y.J.; Li, S.; Gan, R.Y.; Zhou, T.; Xu, D.P.; Li, H.B. Impacts of gut bacteria on human health and diseases. Int. J. Mol. Sci. 2015, 16, 7493–7519.