# Four Dairy Products Mitigates Sarcopenia in Mice by Modulating Muscle Inflammation, Autophagy, and Protein Degradation

## TL;DR

This study shows that consuming certain dairy products, especially fortified goat milk, can help prevent muscle loss in mice by reducing inflammation and improving muscle health.

## Contribution

The study identifies specific dairy products, particularly fortified goat milk, as effective in mitigating sarcopenia through modulation of muscle inflammation and gut microbiota.

## Key findings

- Dairy products increased lean weight and activated the PI3K/Akt/mTOR pathway, with GFM being most effective.
- Dairy intake reduced inflammation markers and enhanced autophagy, as indicated by changes in LC3B and p62 levels.
- Goat milk interventions enriched beneficial gut bacteria, including Leuconostoc and Staphylococcus sciuri.

## Abstract

Sarcopenia, characterized by progressive loss of muscle mass and strength, poses a significant public health challenge. However, the specific role of dairy products in preventing sarcopenia is not well understood. This study investigated the effects of different dairy products on muscle metabolism, focusing on the differences between goat and bovine milk, the impact of dairy fat content, and the potential synergistic effects of vitamin D and calcium. Sixty male C57BL/6 mice (8 months old) were randomly divided into six groups and orally administered with 7 g/kg/day of goat whole milk (GWM), goat low‐fat milk (GLM), goat fortified vitamin D and calcium low‐fat milk (GFM), or bovine whole milk (BWM), respectively. Sarcopenia was induced using intraperitoneal dexamethasone injections (5 mg/kg) for 8 weeks. Grip strength, bone mineral density (BMD), fat and lean weight, muscle morphology, autophagy, inflammation, host metabolism, and gut microbiota were assessed. Sarcopenic mice exhibited decreased lean weight and grip strength. While all dairy products increased lean weight, they did not affect grip strength significantly. At the molecular level, all dairy products activated the PI3K/Akt/mTOR pathway, reduced AMPK phosphorylation, and enhanced muscle regeneration, with GFM being most effective in upregulating MyoG expression. Dairy intake also promoted autophagy by increasing LC3B expression and reducing p62 levels while significantly lowering inflammation markers, including CRP, IL‐1β, IL‐6, and TNF‐α. Gut microbiota analysis revealed that all dairy interventions enriched beneficial genera, with Leuconostoc present in all groups and Acinetobacter and Lactococcus enriched in goat milk groups. Notably, GLM and GFM increased
Staphylococcus sciuri
, which may contribute to muscle health benefits. These findings suggest that dairy consumption, particularly GFM, improves muscle mass, regulates autophagy, reduces inflammation, and modulates gut microbiota composition, providing experimental evidence for sarcopenia prevention and management.

Dairy consumption, particularly goat fortified vitamin D and calcium low‐fat milk, could improve muscle mass and reduce fat weight in sarcopenic mice. Dairy consumption has the potential to improve muscle mass and prevent sarcopenia by modulating autophagy, reducing inflammation, and regulating gut microbiota. The interaction between dairy intake, gut microbiota, and circulating metabolites indicates a potential mechanism for the beneficial effects of dairy in preventing sarcopenia.