Resistant starch (RS), as the name suggests, is a kind of starch that is difficult to digest, but it will be fermented by intestinal microbiota in the colon, which has a positive effect on metabolism. Foods with RS include green bananas, potatoes, sweet potatoes, rice, etc., especially high amylose corn, which contains up to 60% resistant starch. More and more studies have shown that gut microbiota is an important regulator of host physiology and pathology. Specifically, gut microbiota regulates inflammation, fat storage, and glucose metabolism. Combining dietary interventions with fecal microbial transplantation may lead to beneficial changes in the gut microbiota of recipients. Therefore, dietary intervention to control gut microbiota may be a potential strategy for weight loss.

On February 26, 2024, Jia Weiping and Li Huating from the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Xu Aimin from the University of Hong Kong, Liu Xinyu from Dalian Institute of Chemical Physics, Chinese Academy of Sciences and others published a paper in the journal Nature Metabolism entitled "Resistant starch intake" Long-term weight loss in humans by reshaping the gut microbiota ".

Experiments have shown that resistant starch supplementation for only 8 weeks can promote weight loss and improve insulin resistance in overweight individuals, and the benefits of resistant starch are related to changes in gut microbiota composition. Mechanistically, resistant starch-induced changes in gut microbiota alter bile acid distribution, reduce inflammation and inhibit lipid absorption by restoring the intestinal barrier.

In this placebo-controlled, double-blind, cross-over intervention study, researchers analyzed 37 participants, with a mean age of 33.4 years, who were overweight or obese and had a BMI of 24 or more. Participants were randomized into 2 8-week intervention periods during the 20-week continuous study period, and participants were randomized into 2 groups. Participants received one intervention period of resistant starch and one intervention period of control starch, with a 4-week buffer between interventions. The effects of resistant starch as a dietary supplement on obesity and other metabolic phenotypes were analyzed. During the 8-week intervention period, the intervention group received 40 g resistant starch daily and the control group received 0 g resistant starch daily. In addition, an isoenergetic and balanced diet was provided to participants in both groups. The study found that participants who received resistant starch for 8 weeks lost an average of 2.8 kg of body weight and had significant reductions in fat mass and waist circumference compared with those in the control starch group.

On September 5, 2023, Jia Weiping, Li Huating and other researchers from the Sixth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine published an article entitled "Resistant starch decreases intrahepatic triglycerides in" in the journal "Cell Metabolism" The research paper "patients with NAFLD via gut microbiome alterations" was on the cover of the current journal. Studies have shown that a diet rich in resistant starch can change the composition of intestinal bacteria, reduce the levels of triglyceride and liver enzymes related to liver injury and inflammation, and reduce fatty liver.

In summary, the results showed that resistant starch supplementation could help to reduce body weight and improve insulin sensitivity in overweight individuals, reduce the levels of triglyceride and liver enzymes associated with liver injury and inflammation, and reduce fatty liver. The benefits of resistant starch supplementation were related to the changes in gut microbiota composition.