Impact of short-term overfeeding of saturated or unsaturated fat or sugars on the gut microbiota in relation to liver fat in obese and overweight adults

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Backgrounds & aims: Intestinal microbiota may be causally involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). We aimed to study the effect of short-term overfeeding on human gut microbiota in relation to baseline and overfeeding-induced liver steatosis. We also asked whether the baseline microbiota composition is associated to the overfeeding-induced increase in liver fat.

Methods: In a randomized trial, 38 overweight and obese subjects were assigned to consume an excess of 1000 kcal/day of diets rich in either saturated fat, unsaturated fat, or simple sugars for 3 weeks. Fasting blood samples and H-1-MR spectroscopy were used for extensive clinical phenotyping as previously reported (PMID: 29844096). Fecal samples were collected for the analysis of the gut microbiota using 16S rRNA amplicon sequencing, imputed metagenomics and qPCR. Microbiota results were correlated with dietary intakes and clinical measurements before and during overfeeding.

Results: The overall community structure of the microbiota remained highly stable and personalized during overfeeding based on between-sample Bray-Curtis dissimilarity, but the relative abundances of individual taxa were altered in a diet-specific manner: overfeeding saturated fat increased Proteobacteria, while unsaturated fat increased butyrate producers. Sugar overfeeding increased Lactococcus and Escherichia coli. Imputed functions of the gut microbiota were not affected by overfeeding. Several taxa affected by overfeeding significantly correlated with the changes in host metabolic markers. The baseline levels of proteobacterial family Desulfovibrionaceae, and especially genus Bilophila, were significantly associated to overfeeding-induced liver fat increase independently of the diet arm. In general, limited overlap was observed between the overfeeding-induced microbiota changes and the liver fat-associated microbiota features at baseline.

Conclusions: Our work indicates that the human gut microbiota is resilient to short-term overfeeding on community level, but specific taxa are altered on diet composition-dependent manner. Generalizable microbiota signatures directly associated with liver steatosis could not be identified. Instead, the carriage of Bilophila was identified as a potential novel risk factor for diet-induced liver steatosis in humans. (C) 2020 Published by Elsevier Ltd.

Original languageEnglish
JournalClinical Nutrition
Volume40
Issue number1
Pages (from-to)207-216
Number of pages10
ISSN0261-5614
DOIs
Publication statusPublished - Jan 2021
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 3121 General medicine, internal medicine and other clinical medicine
  • 3143 Nutrition
  • Intestinal microbiota
  • Overfeeding
  • Saturated fat
  • Unsaturated fat
  • Sugar
  • Liver fat
  • INTESTINAL MICROBIOTA
  • DIETARY-FAT
  • HEPATIC STEATOSIS
  • DISEASE
  • METABOLISM
  • PERMEABILITY
  • MODULATION
  • DYSBIOSIS

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