Changes in the nutrients of camels’ milk alter the functional features of the intestine microbiota

Abstract

Heat treatment alters the nutritive quality of camels' milk and thus the intestine microbiota, but the effect of heat treatment-induced nutrient loss on the functional features of the intestine microbiota is unknown. In this study, the influence of two heat treatments of camels’ milk on the intestine microbiota was investigated to establish the correlations between milk nutrients and the functional features of the intestine microbiota. Camels’ milk, heat treated at low (65 °C) or high (100 °C) temperatures, was administered to mice (LM = low; HM = high); control mice received sterile distilled water (CW = control). Intestine microbiota were compared in the three groups using metagenomic-based 16S rRNA gene high throughput sequencing. The results showed that the relative abundance of probiotic genera (Akkermansia, Bifidobacterium and Lactobacillus) was significantly higher in the LM group mice than in the HM group mice, due to the high-temperature degradation of the nutrients of camels’ milk. The diversity of the intestine microbiota in mice receiving milk was lower than in the control group because of the intrinsically high antimicrobial components (lactoferrin and lysozyme) detected in camels’ milk. Carbohydrate digestion/absorption, and cysteine and methionine metabolism were significantly higher in the intestine microbiota of the LM group mice than in the HM group mice owing to the corresponding degradation of lactose, cysteine and methionine in camels’ milk at high temperatures. Changes in the nutrients of camels’ milk affected the changes in the functional features of the intestine microbiota. This research suggests that low temperature heat treatment achieves nutrient preservation, but also encourages probiotic genera.