Effect of a Chinese medical nutrition therapy diet on gut microbiota and short chain fatty acids in the simulator of the human intestinal microbial ecosystem (SHIME)

Liver fat as a dietary target by Chinese Medical Nutrition Therapy (CMNT) diet for treating type 2 diabetes with non-alcoholic fatty liver disease: study protocol for a randomised controlled trial

INTRODUCTION

Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) often coexist and increase risk for developing liver fibrosis and diabetes complications if no effective measures are taken. Dietary intervention is known to be able to achieve diabetes remission, while evidence regarding the long-term effect on liver fat is limited for comorbidity management of type 2 diabetes and NAFLD. This study aims to investigate the long-term effect of a Chinese Medical Nutrition Therapy (CMNT) diet accompanied by intermittent energy restriction on reducing liver fat and glycated haemoglobin (HbA1c) in patients with type 2 diabetes and NAFLD.

METHODS AND ANALYSIS

This is a multicentre two-armed parallel randomised controlled trial study. 120 participants with type 2 diabetes and NAFLD will be recruited from the physical examination centres of multiple hospitals in China. Participants will be randomly allocated 1:1 to either the CMNT group or the usual care group. The CMNT group will be instructed to consume the provided specific meal replacement Chinese medicinal foods consisting of 6 cycles of 5 consecutive days followed by 10 days of regular food intake. The usual care group will be given standard dietary advice. Primary outcomes are changes in the controlled attenuation parameter value by transient elastography and HbA1c level. Secondary outcomes include differences in anthropometrics, clinical blood markers, questionnaires, gut microbiota and metabolomics. Further follow-up will be performed at 6 months, 1 year and 2 years.

ETHICS AND DISSEMINATION

The study protocol was approved by the Biomedical Research Ethics Committee of Hunan Agricultural University (BRECHAU20200235).The results will be disseminated via relevant peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05439226.

Integrated Analysis of Gut Microbiome and Adipose Transcriptome Reveals Beneficial Effects of Resistant Dextrin from Wheat Starch on Insulin Resistance in Kunming Mice

Systemic chronic inflammation is recognized as a significant contributor to the development of obesity-related insulin resistance. Previous studies have revealed the physiological benefits of resistant dextrin (RD), including obesity reduction, lower fasting glucose levels, and anti-inflammation. The present study investigated the effects of RD intervention on insulin resistance (IR) in Kunming mice, expounding the mechanisms through the gut microbiome and transcriptome of white adipose. In this eight-week study, we investigated changes in tissue weight, glucose-lipid metabolism levels, serum inflammation levels, and lesions of epididymal white adipose tissue (eWAT) evaluated via Hematoxylin and Eosin (H&E) staining. Moreover, we analyzed the gut microbiota composition and transcriptome of eWAT to assess the potential protective effects of RD intervention. Compared with a high-fat, high-sugar diet (HFHSD) group, the RD intervention significantly enhanced glucose homeostasis (e.g., AUC-OGTT, HOMA-IR, p < 0.001), and reduced lipid metabolism (e.g., TG, LDL-C, p < 0.001) and serum inflammation levels (e.g., IL-1β, IL-6, p < 0.001). The RD intervention also led to changes in the gut microbiota composition, with an increase in the abundance of probiotics (e.g., Parabacteroides, Faecalibaculum, and Muribaculum, p < 0.05) and a decrease in harmful bacteria (Colidextribacter, p < 0.05). Moreover, the RD intervention had a noticeable effect on the gene transcription profile of eWAT, and KEGG enrichment analysis revealed that differential genes were enriched in PI3K/AKT, AMPK, in glucose-lipid metabolism, and in the regulation of lipolysis in adipocytes signaling pathways. The findings demonstrated that RD not only ameliorated IR, but also remodeled the gut microbiota and modified the transcriptome profile of eWAT.

Effect of an Intermittent Calorie-restricted Diet on Type 2 Diabetes Remission: A Randomized Controlled Trial

CONTEXT

The 2021 consensus report on the definition and interpretation of remission of type 2 diabetes (T2D) has been released. Although intermittent fasting diets (IF) are becoming very popular, no studies have investigated their benefit in diabetes remission.

OBJECTIVE

The present study examined the effectiveness of IF in diabetes remission and potential remission durability.

METHODS

Participants between ages 38 and 72 years with a duration of T2D of 1 to 11 years, a body mass index (BMI) of 19.1 to 30.4, 66.7% male, and antidiabetic agent use and/or insulin injection were randomly allocated at a ratio of 1:1 to the Chinese Medical Nutrition Therapy (CMNT) or control group. The primary outcome was diabetes remission, defined as a stable glycated hemoglobin A1c (HbA1c) level of less than 48 mmol/mol (< 6.5%) for at least 3 months after discontinuing all antidiabetic medications. The secondary outcomes included HbA1c level, fasting blood glucose level, blood pressure, weight, quality of life, and medication costs. We conducted a 12-month follow-up to assess the continuation of remission.

RESULTS

On completing the 3-month intervention plus 3-month follow-up, 47.2% (17/36) of participants achieved diabetes remission in the CMNT group, whereas only 2.8% (1/36) of individuals achieved remission in the control group (odds ratio 31.32; 95% CI, 2.39-121.07; P < 0.0001). The mean body weight of participants in the CMNT group was reduced by 5.93 kg (SD 2.47) compared to 0.27 kg (1.43) in the control group. After the 12-month follow-up, 44.4% (16/36) of the participants achieved sustained remission, with an HbA1c level of 6.33% (SD 0.87). The medication costs of the CMNT group were 77.22% lower than those of the control group (60.4/month vs 265.1/month).

CONCLUSION

This study demonstrated the clinical efficacy of CMNT in achieving diabetes remission for at least 1 year.

Anti-diabetic and gut microbiota modulation effects of sacha inchi (Plukenetia volubilis L.) leaf extract in streptozotocin-induced type 1 diabetic mice

BACKGROUND

Sacha inchi (Plukenetia volubilis L.) tea has been used as an adjuvant treatment for diabetes in Pu'er, in the Yunnan province of China. The effects of sacha inchi tea on diabetes and the underlying mechanisms remain unknown. This study was conducted to investigate the influence of a water extract of sacha inchi (P. volubilis L.) leaves (PWE) on hypoglycemic activity and gut microbiota composition in mice with streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM). During the 6 weeks of the study, T1DM mice were administered PWE intragastrically at 400 mg kg^-1 body weight (BW) per day.

RESULTS

Treatment with PWE reduced excessive loss of BW and excessive intake of food. It significantly decreased blood glucose levels and improved oral glucose tolerance. The treatment caused protective histopathological transformations in sections of the pancreas, leading to decreased insulin resistance and improved insulin sensitivity. Treatment with PWE also significantly ameliorated disorders of the gut microbiota structure and increased the richness and diversity of intestinal microbial species in T1DM mice. At the genus level, the populations of several crucial bacteria, such as Akkermansia, Parabacteroides, and Muribaculum increased in the PWE treatment group but the abundance of Ruminiclostridium and Oscillibacter decreased.

CONCLUSIONS

Treatment with PWE can ameliorate hyperglycemic symptoms in STZ-induced T1DM mice, and the anti-diabetic effect of PWE was related to the amelioration of gut microbial structural disorder and the enrichment of functional bacteria. © 2022 Society of Chemical Industry.

Nutritional Effects of the Enteral Nutritional Formula on Regulation of Gut Microbiota and Metabolic Level in Type 2 Diabetes Mellitus Mice

PURPOSE

Due to the adverse effects of antidiabetic drugs, nowadays, nutraceuticals have been of much interest to investigators. Therefore, the present study aimed to explore the potential effects of enteral nutritional (EN) formulas on the gut microbiota and metabolic regulation of type 2 diabetes mellitus (T2DM) mice and compare the differences between whey protein and soy protein.

METHODS

EN formulas made of whey protein or soy protein were administered for five weeks and then mice tissue samples were obtained to examine the metabolic parameters and histopathology of the pancreas, liver, jejunum and colon. 16S rRNA V3-V4 region gene sequencing was used to analyze the changes in the gut microbiota.

RESULTS

After the five-week intervention, the alpha diversity had recovered slightly, and the soy protein group (SPG) achieved a better effect than the whey protein group (LPG). The overall composition of gut microbiota was regulated. The abundance of Bacteroidetes and TM7 had raised significantly and the abundance of Firmicutes and Deferribacteres had declined after treatment, with no significant difference between the LPG and SPG. The types of beneficial bacteria were increased at the genus and species level. The level of hexokinase (HK) and pyruvate kinase (PK) had significantly recovered and inhibited the level of α-glucosidase. In addition, the EN formulas treatment reduced the levels of inflammatory factor (TNF-α) in liver and muscle. The level of glucose transporter type 2 (GLUT-2) levels in the liver and intestine also significantly increased. Moreover, the metabolism regulation of the SPG was better than that of the LPG. The EN formulas treatment improved the pancreas, liver, jejunum and colon histology.

CONCLUSION

The EN formulas regulated the overall structure of the gut microbiota and improved the metabolic level in streptozotocin/high-fat diet (STZ/HFD) diabetic mice. Therefore, EN formula may potentially become an effective nutritional adjunctive therapy for T2DM.

Marine polysaccharides from Gelidium pacificum Okamura and Cereus sinensis reveal prebiotic functions

Many marine polysaccharides as prebiotics can promote host health by modulating gut microbiota. This study investigated the beneficial effects of purified marine plant-derived Gelidium pacificum Okamura polysaccharide (GPOP-1) and marine animal-derived Cereus sinensis polysaccharide (CSP-1) on normal mice by modulating gut microbiota. The composition and diversity of gut microbiota were evaluated using 16S rRNA high-throughput sequencing. The results showed that GPOP-1 and CSP-1 altered the composition of the gut microbiota and promoted the growth of beneficial bacteria. At the genus level, GPOP-1 increased the relative abundance of Bacteroides, Phascolarctobacterium, and decreased the relative abundance of Ruminococcus, Helicobacter, Allobaculum, Dorea and AF12. While CSP-1 increased the relative abundance of Coprococcus, Adlercreutzia, Roseburia, Phascolarctobacterium, and decreased the relative abundance of Bacteroides, Ruminococcus and Oscillospira. The changes in the gut microbiota may affect the body weight, immune organ index and the production of short-chain fatty acids in normal mice. Compared to the normal control group, GPOP-1 decreased average weight gain while CSP-1 increased average weight gain. Furthermore, both GPOP-1 and CSP-1 significantly increased thymus and spleen indexes and total short chain fatty acids production in mice. In summary, GPOP-1 and CSP-1 exerted prebiotic effects on normal mice.

Enhanced thermal stability of green banana starch by heat-moisture treatment and its ability to reduce body fat accumulation and modulate gut microbiota

The physicochemical properties (including morphology, pasting, and thermal properties) of resistant starch (RS) in green banana starch were analyzed after the heat-moisture treatment in the presence of citric acid (CAHMT) at different temperatures. Moreover, this study evaluated whether the administration of CAHMT banana starch could reduce body fat accumulation and modulate gut microbiota. Our results demonstrated that the CAHMT process (90 °C) resulted in a higher retention (80.9%) and thermal stability of RS, alteration in the crystalline structure of starch from B-type to A-type, and increased solubility (27.9-fold) and gelatinization temperatures (from 66.26-78.89 °C to 81.48-92.11 °C). A reduction in swelling power (-57.7%) and a loss of pasting viscosity were also noted. Even after a 30 min boil, the retention rate of residual RS (CAHMT at 90 °C) was up to 50% (4.3-fold higher than the control). Rats fed the CAHMT banana starch resulted in significantly (p < 0.05) lower total visceral fat (-18.1%) and Firmicutes to Bacteroidetes ratio as well as higher total fecal short chain fatty acids. The CAHMT process at 90 °C enhanced the thermal stability of banana RS allowing a wider range of applications in functional foods.

Bifidobacterium longum subsp. longum Remodeled Roseburia and Phosphatidylserine Levels and Ameliorated Intestinal Disorders and liver Metabolic Abnormalities Induced by High-Fat Diet

Bifidobacterium longum is considered as a potential supplement in antiobesity treatment; however, the underlying molecular mechanism has rarely been studied. To understand the contributions of B. longum subsp. longum (BL21) in the prevention of obesity, we investigated alterations in the liver metabonomic phenotype and gut microbiota by ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and 16S ribosomal RNA gene sequencing in C57BL/6J male mice orally administered with BL21 for 8 weeks [high-fat diet (HFD)]. BL21 at 1 × 109 CFU·day-1 per mouse reduced the weight of mice by 16.9% relative to that of the mice fed with HFD and significantly lowered the serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol. BL21 also ameliorated fat vacuolization in liver cells and epididymal fat accumulation. BL21 also lowered the Firmicutes/Bacteroidetes ratio, regulated liver remodeling in glycerophospholipids, and alleviated the levels of d-tryptophan. A positive correlation between the butyrate-producing strain Roseburia and the cell membrane component phosphatidylserine was found for the first time. Thus, BL21 can potentially prevent mice from being obese by rebalancing the gut microbiota and glycerophospholipid metabolism. BL21 can be a promising dietary supplement for weight control.