Linoleic acid inhibits Lactobacillus activity by destroying cell membrane and affecting normal metabolism

Abstract

BACKGROUND The reason why dietary polyunsaturated fatty acids (PUFAs) affect the activity of Lactobacillus remains unclear. In this study, linoleic acid was used to study the mechanism underlying its inhibition function against Lactobacillus activity. RESULTS The growth curve of Lactobacillus rhamnosus LGG and the metabolite content in bacterial liquid were determined at varying linoleic acid concentration. The degree of cell membrane damage of L. rhamnosus LGG was determined by flow cytometry and fluorescence microscopy, and the cell structure was observed by scanning electron microscopy and transmission electron microscopy. The effect of linoleic acid on Lactobacillus activity was assessed in a simulated gut environment. Results showed that L. rhamnosus LGG grew slowly, cell metabolites leaked into the liquid, cell membrane was damaged, and the cell structure changed at a linoleic acid concentration of 50 μg mL−1. CONCLUSION The mechanism of action of linoleic acid on Lactobacillus showed that that linoleic acid destroyed the cell membrane of bacteria, thereby affecting the normal metabolism of the bacteria and ultimately leading to their death. © 2019 Society of Chemical Industry

Protective Effects of Intestinal Gallic Acid in Neonatal Dairy Calves Against Extended-Spectrum β-lactamase Producing Enteroaggregative Escherichia coli Infection: Modulating Intestinal Homeostasis and Colitis

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n-6 High Fat Diet Induces Gut Microbiome Dysbiosis and Colonic Inflammation

“…This microbial imbalance may be due to altered levels of fatty acids in the intestine [43] with LA inhibiting growth of bacteria of the Firmicutes phylum (i.e., Lactobacillus spp.) [49]. The gut abundance of Firmicutes is decreased in HFD-fed mice by LA supplementation, which however sustains the expansion of Lactobacillaceae [50].…”

Oleate Hydratase in Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230 Catalyzes the Reversible Conversion between Linoleic Acid and Ricinoleic Acid

“…The nature of LA inhibitory activity remains unknown. Nevertheless, some authors have associated it with an increase in the permeability of the cell membrane of bacteria ( 30 , 31 ). Volkov et al ( 21 ) hypothesized that the hydration of unsaturated fatty acids could provide a detoxification mechanism of unsaturated fatty acids’ detrimental effect on the cytoplasmic membrane.…”