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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #415109
Research Project: Prevention of Obesity Related Metabolic Diseases by Bioactive Components of Food Processing Waste Byproducts and Mitigation of Food Allergies

Location: Healthy Processed Foods Research

Title: Dynamic hydration and viscosity control of konjac glucomannan enhance long-term antiobesity effects by reducing food intake in high-fat-diet-fed mice

Author
item GUO, LIPING - Jiangnan University
item Yokoyama, Wallace
item CHEN, LING - Jiangnan University
item CHEN, MAOSHEN - Jiangnan University
item ZHONG, FANG - Jiangnan University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2024
Publication Date: 10/23/2024
Citation: Guo, L., Yokoyama, W.H., Chen, L., Chen, M., Zhong, F. 2024. Dynamic hydration and viscosity control of konjac glucomannan enhance long-term antiobesity effects by reducing food intake in high-fat-diet-fed mice. Journal of Agricultural and Food Chemistry. 72(44):24561-24575. https://doi.org/10.1021/acs.jafc.4c07730.
DOI: https://doi.org/10.1021/acs.jafc.4c07730

Interpretive Summary: Viscous soluble dietary fibers are known to reduce glycemic index, plasma cholesterol, and reduce or prevent other characteristics of metabolic dysfunction. Konjac mannan (KGM) is a highly viscous carbohydrate polymer formulated in some foods for its healthful properties. In this study we show that its viscous behavior is dependent on rate of hydration or water retention in different parts of the digestive tract. Further the molecular weight of KGM can be tuned to optimize physiological effects.

Technical Abstract: The purpose of this study was to investigate the necessity and importance of dynamic hydration rate and ultimate viscosity control of KGM to long-term anti-obesity inC57BL/6J mice on high fat (HF) diets. KGM supplementations attenuate HF diet induced body weight and tissue weight gain. The hydration rate and viscosity increase of KGM in the digestive tract have marked impacts on anti-obesity effects. KGM with medium hydration rate and viscosity slowed gastric emptying as well as intestinal food migration and its longer presence in the lower ileum stimulates a higher secretion of satiety related hormones (GLP-1 and PYY were 1.27 and 1.16 times that of HF group, respectively). It decreased mean daily intake during the ten-week study by 18.27%compared with HF group (p < 0.05), and best reduced weight gain on HF diets. The two fast hydration and high viscosity KGM produces a short-term satiety, but due to the dilution in the digestive tract, viscosity decreases rapidly, the satiety effect cannot be maintained, and may cause rebound of strong appetite and higher food intake. KGM supplementations ameliorated fasting blood glucose, glucose tolerance, lipid homeostasis and liver injury in HF-fed mice. KGM reduced biomarkers of metabolic dysfunction by enhancing the antioxidant defense system, inhibiting production of inflammatory cytokines and adipocytokines. Furthermore, KGM supplementation led to significant changes in transcription of genes related to glycolipid metabolism and had a profound impact on the gut microbiome composition and abundance with enrichment of beneficial bacteria. There was no significant difference in the ability of the KGM to regulate gene transcription or the gut microbiome. These results suggest that the hydration rate and viscosity increase of KGM in synchrony with digestive processes are the key factors that regulate satiety hormones and reduce food intake resulting in long-term weight loss.