Germinated Millet (Pennisetum glaucum (L.) R. Br.) Flour Improved the Gut Function and Its Microbiota Composition in Rats Fed with High-Fat High-Fructose Diet

Int J Environ Res Public Health. 2022 Nov 18;19(22):15217. doi: 10.3390/ijerph192215217.

Abstract

Germinated millet (Pennisetum glaucum (L.) R. Br.) is a source of phenolic compounds that has potential prebiotic action. This study aims at evaluating the action of germinated pearl millet on gut function and its microbiota composition in Wistar rats fed with a high-fat high-fructose (HFHF) diet. In the first stage, lasting eight weeks, the experiment consisted of two groups: AIN-93M (n = 10) and HFHF group (n = 20). In the second stage, which lasted ten weeks, the animals of the AIN-93M group (n = 10) were kept, while the HFHF group was dismembered into HFHF (HFHF diet, n = 10) and HFHF + millet (HFHF added 28.6% of germinated millet flour, n = 10) groups. After the 18th week, the urine of the animals was collected for the analysis of lactulose and mannitol intestinal permeability by urinary excretion. The histomorphometry was analyzed on the proximal colon and the fecal pH, concentration of short-chain fatty acids (SCFA), and sequencing of microbiota were performed in cecum content. The Mothur v.1.44.3 software was used for data analysis of sequencing. Alpha diversity was estimated by Chao1, Shannon, and Simpson indexes. Beta diversity was assessed by PCoA (Principal Coordinate Analysis). The functional predictive analysis was performed with PICRUSt2 software (version 2.1.2-b). Functional traits attributed to normalized OTU abundance were determined by the Kyoto Encyclopedia of Genes and Genomes (KEGG). In the results, germinated millet flour reduced Oscillibacter genus and Desulfobacterota phylum, while increasing the Eggerthellaceae family. Furthermore, germinated millet flour: increased beta diversity, cecum weight, and cecum/body weight ratio; improved gut histological parameters by increasing the depth and thickness of the crypt and the goblet cell count (p < 0.05); reduced (p < 0.05) the fecal pH and mannitol urinary excretion; increased (p < 0.05) the propionate short-chain fatty acid concentration. Thus, germinated millet has the potential to improve the composition of gut microbiota and the intestinal function of rats fed with an HFHF diet.

Keywords: beta diversity; goblet cells; intestinal health; intestinal permeability; prebiotic; whole grain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diet, High-Fat
  • Edible Grain / chemistry
  • Fatty Acids, Volatile
  • Flour / analysis
  • Fructose
  • Gastrointestinal Microbiome*
  • Mannitol / analysis
  • Millets
  • Pennisetum*
  • Rats
  • Rats, Wistar

Substances

  • Fructose
  • Fatty Acids, Volatile
  • Mannitol

Grants and funding

Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil) [Grant number: 001], Institutional Internationalization Program-CAPES (CAPES-PrInt) [Grant number: 88887.511858/2020-00], National Counsel of Technological and Scientific Development (CNPq, Brazil) [Grant number: 001], and the Foundation for Research Support of Minas Gerais (FAPEMIG, Brazil) which provided a scholarship. This work was supported by Embrapa Food Technology, Brazil [Grant number: 13.16.05.043. 00.00] and the Foundation of Rio de Janeiro (FAPERJ/Brazil) [Grant number: E-26/202.848/2017].