**4.2 Prebiotics and probiotics**

Recently prebiotics and probiotics have gained a lot of popularity among individuals as a healthy substitute for antibiotics. Prebiotics are actually indigestible carbohydrates that improve the growth and function of colonic bacteria boosting host health. Prebiotics include oligosaccharides which cannot be digested in the upper GI tract. These oligosaccharides are fermented, producing SCFAs in the colon and result in stimulation of growth of colonic. Prebiotics can be obtained from a large number of dietary elements like barley, garlic, asparagus, wheat bran and onions and both prebiotics and probiotics can be obtained from pickled and fermented foods like sauerkraut, kimchi, miso, yogurt [15, 16]. Probiotics obtained from food and supplements contain some very popular strains like bifidobacteria and lactobacilli. These bacteria alter the composition and function of GM as well as host system activity. The prebiotics and probiotics compete with pathogenic


**165**

**5. Conclusion**

*An Insight into the Changing Scenario of Gut Microbiome during Type 2 Diabetes*

and enhances the immune system (**Table 2**) [15, 16, 115].

pro-inflammatory bacterial strains (**Table 2**) [124].

bacteria, intensify the intestinal barrier by secreting some antimicrobial substances

Changes in diet plan can modulate activity of GM and host metabolism. A fat and carbohydrate restricted diet increased the ratio of Bacteroidetes to Firmicutes in obese patients with T2D [118]. Also calorie deficient diet plans or diet plans rich in high-fiber macrobiotics like complex carbohydrates, legumes, fermented products, sea salt, and green tea and free of animal protein fat, and added sugar improved dysbiosis, increased GM ecosystem diversity, and enhanced SCFA producers in T2D patients. Macrobiotic diet can more efficiently reduce fasting and postprandial glucose, A1C, serum cholesterol, insulin resistance, BMI, waist and hip circumferences than the control diet. Also macrobiotic diet could effectively reduce

Metformin, already a well-established drug for T2D, has recently been known to have bacterio-therapeutic effects on microbial composition and production of SCFA. Several recent reports have shown that metformin affects GM of T2D patients like increasing the levels of butyrate-producing bacteria. Metformin can also decrease

Fecal microbiota transplant, or stool transplant also called bacteriotherapy, which is the process of replacing fecal bacteria from a healthy individual into a host individual has been quite effective in restoring GM composition. Fecal microbiota transplant is used in treating recurrent *Clostridium difficile colitis* recharging useful bacteria in the GI tract along with usage of antibiotics. Autologous infusion is reinfusion of one's collected feces and allogenic infusion is infusion with feces from a donor. Insulin resistant adults when autologously transplanted did not alter the GM composition but when transplanted with allogenic infusion from lean donors exhibited significant rise in GM diversity, enhanced levels of butyrate producing

Bariatric surgery, or Roux-en-Y gastric bypass (RYGBP), is removal of a portion of stomach and re-routing the small intestine to a small stomach pouch. It is performed on people as an efficient tool to treat obesity. After bariatric surgery huge changes occur in the GM, Proteobacteria rises and Firmicutes and Bacteroides lowers, BMI reduces by 15–32%, C-reactive protein decreases and T2DM is attenuated. However, increase in some bacteria are highly significant than the normal levels in lean controls, which means these alterations are linked with GM modification, and

The GM makes one of the largest organs in human body and remains the reason behind various metabolic disorders such as obesity, atherosclerosis, type 2 diabetes

the levels of Lactobacillus which remains high in T2D patients (**Table 2**) [125].

bacteria and improved sensitivity to insulin (**Table 2**) [114, 115].

*DOI: http://dx.doi.org/10.5772/intechopen.90697*

**4.3 Dietary modulation**

**4.4 Metformin**

**4.5 Fecal microbiota transplant**

**4.6 Bariatric surgery**

not body weight (**Table 2**) [112, 117, 118].

**Table 2.** *Types of treatments for T2D involving modulation of GM and their effects.* bacteria, intensify the intestinal barrier by secreting some antimicrobial substances and enhances the immune system (**Table 2**) [15, 16, 115].
