A meta-analysis of the effect of probiotic administration on age-related sarcopenia

Systemic inflammation is associated with gut microbiota diversity in post-stroke patients

BACKGROUND

There is growing interest in gut microbiota and health outcomes. However, the relationship between systemic inflammation and gut microbiota diversity in hospitalized patients remains unclear. This study aimed to investigate the association in post-stroke rehabilitation patients.

METHODS

A cross-sectional study was conducted on post-stroke patients admitted to a rehabilitation hospital. Systemic inflammation was assessed using the modified Glasgow Prognostic Score (mGPS). Gut microbiota diversity was evaluated using three indices: Shannon index, Operational Taxonomic Unit (OTU) richness, and Faith's Phylogenetic Diversity (PD). Multiple linear regression analyses were performed to examine the relationship between mGPS and gut microbiota diversity indices, adjusting for potential confounders.

RESULTS

A total of 156 patients (mean age 78.4 years; 55.7% men) were analyzed. The median mGPS was 0 (interquartile range: 0-1), with GPS distribution: 61.8% scored 0, 25.7% scored 1, and 12.5% scored 2. After adjusting for confounders, mGPS was significantly and negatively associated with the Shannon index (B = -0.143, 95% CI -0.288 to -0.002, β = -0.177) and OTU richness (B = -17.832, 95% CI -24.349 to -3.951, β = -0.208). However, no significant association was observed between mGPS and Faith's PD (B = -1.155, 95% CI -2.464 to 0.189, β = -0.155).

CONCLUSION

This study demonstrates a significant negative association between systemic inflammation and both quantitative and qualitative gut microbiota diversity in post-stroke patients.

Gut microbiome diversity is associated with muscle mass, strength and quality in post-stroke patients

BACKGROUND

The gut microbiome has emerged as a potential influencer of muscle health; however, its role in hospitalized patients remains unclear. This study aimed to investigate the association between gut microbiome diversity and skeletal muscle mass, strength, and quality in hospitalized post-stroke patients.

METHODS

We conducted a cross-sectional study of post-stroke patients admitted to a rehabilitation facility. Gut microbiome diversity was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing, calculating Operational Taxonomic Unit (OTU) Richness, Faith's Phylogenetic Diversity (PD), and Shannon index. Muscle health was evaluated using skeletal muscle index (SMI) for muscle mass, handgrip strength (HGS) for muscle strength, and bioimpedance analysis-derived phase angle (PhA) for muscle quality. Multiple linear regression analyses were performed, adjusting for potential confounders.

RESULTS

A total of 156 patients (mean age 78.4 years; 55.7 % male) were analyzed. OTU Richness showed significant positive associations with SMI (β = 0.197, p = 0.025), HGS (β = 0.180, p = 0.005), and PhA (β = 0.178, p = 0.022). The Shannon index was also positively associated with SMI (β = 0.120, p = 0.041), HGS (β = 0.140, p = 0.028), and PhA (β = 0.164, p = 0.032). Faith's PD did not demonstrate significant associations with muscle health parameters.

CONCLUSIONS

Higher gut microbiome diversity, assessed by OTU Richness and Shannon index, is associated with better muscle mass, strength, and quality in post-stroke patients. These findings suggest a potential role for gut microbiota in muscle health during stroke rehabilitation.

Gut dysbiosis in primary sarcopenia: potential mechanisms and implications for novel microbiome-based therapeutic strategies

Primary sarcopenia is characterized by a progressive loss of skeletal muscle mass, strength, and physical function that occurs with aging. Despite the related adverse or even serious health outcomes, no medications are currently available for treating primary sarcopenia. Here, we discuss recent advancements in understanding the mechanistic role of gut microbiota-muscle cross-talk in primary sarcopenia, and the therapeutic implications. The mechanistic insights encompass a causal role of gut dysbiosis in primary sarcopenia, potentially mediated through gut microbiota-derived bioactive metabolites, such as short-chain fatty acids (SCFAs), secondary bile acids, and their associated signaling pathways, which may be translated into the development of new microbiome-based treatment and diagnostic approaches. Furthermore, we identify challenges that need addressing in future studies to facilitate the translation into potential novel treatment and differential diagnosis for older individuals with sarcopenia.

Enhancement of Lower Limb Muscle Strength and Reduction of Inflammation in the Elderly: A Randomized, Double-Blind Clinical Trial Comparing Lacticaseibacillus paracasei PS23 Probiotic with Heat-Treated Supplementation

Background: As individuals age, there is a gradual loss of muscle mass and strength, which not only impairs physical functionality but also heightens the risk of falls and diminishes independence among older adults. Probiotics have emerged as a focus of recent research due to their potential role in enhancing muscle health via the gut-muscle axis. This study evaluates the effects of live and heat-treated Lacticaseibacillus paracasei PS23 (PS23) supplementation on muscle strength and mass in the elderly. Methods: This study recruited 119 participants, aged 65-85 years, and randomly assigned them to receive a placebo (0 × 1010 CFU/day), L-PS23 (live PS23, 2 × 1010 CFU/day), or HT-PS23 (heat-treated PS23, 2 × 1010 cells/day) for a duration of 12 weeks. Assessments of blood pressure, body composition, muscle strength, functional physical fitness, and biochemical parameters were conducted at baseline, 6 weeks, and 12 weeks. Results: Among the 100 subjects who completed the trial, supplementation with both L-PS23 and HT-PS23 significantly enhanced lower limb muscle strength and endurance compared to the placebo (p < 0.05), although no significant differences were observed in muscle mass or upper limb muscle strength across the groups. Additionally, while most muscle anabolism-related markers showed no significant changes, both supplements effectively decreased inflammatory markers related to aging-C-reactive protein (CRP: L-PS23, p = 0.016; HT-PS23, p = 0.013) and interleukin-6 (IL-6: L-PS23, p = 0.003; HT-PS23, p < 0.001)-and increased interleukin-10 levels (L-PS23, p = 0.014; HT-PS23, p = 0.005). Notably, only the HT-PS23 group demonstrated a significant increase in testosterone levels (p = 0.029). Conclusions: 12 weeks of supplementation with L-PS23 and HT-PS23 improved lower limb muscle strength and endurance but did not significantly enhance muscle mass in older adults. Both supplements also proved effective in reducing inflammatory markers and elevating testosterone levels. HT-PS23, administered as a heat-treated probiotic, provided more pronounced benefits to the elderly compared with its probiotic counterpart, L-PS23.

Sarcopenia and the biological determinants of aging: A narrative review from a geroscience perspective

BACKGROUND

The physiopathology of sarcopenia shares common biological cascades with the aging process, as does any other age-related condition. However, our understanding of the interconnected pathways between diagnosed sarcopenia and aging remains limited, lacking sufficient scientific evidence.

METHODS

This narrative review aims to gather and describe the current evidence on the relationship between biological aging determinants, commonly referred to as the hallmarks of aging, and diagnosed sarcopenia in humans.

RESULTS

Among the twelve hallmarks of aging studied, there appears to be a substantial association between sarcopenia and mitochondrial dysfunction, epigenetic alterations, deregulated nutrient sensing, and altered intercellular communication. Although limited, preliminary evidence suggests a promising association between sarcopenia and genomic instability or stem cell exhaustion.

DISCUSSION

Overall, an imbalance in energy regulation, characterized by impaired mitochondrial energy production and alterations in circulatory markers, is commonly associated with sarcopenia and may reflect the interplay between aging physiology and sarcopenia biology.

Lactobacillus sp. for the Attenuation of Metabolic Dysfunction-Associated Steatotic Liver Disease in Mice

Probiotics are studied for their therapeutic potential in the treatment of several diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD). Part of the significant progress made in understanding the pathogenesis of steatosis has come from identifying the complex interplay between the gut microbiome and liver function. Recently, probiotics have shown beneficial effects for the treatment and prevention of steatosis and MASLD in rodent models and in clinical trials. Numerous studies have demonstrated the promising potential of lactic acid bacteria, especially the genus Lactobacillus. Lactobacillus is a prominent bile acid hydrolase bacterium that is involved in the biotransformation of bile acids. This genus' modulation of the gut microbiota also contributes to overall gut health; it controls gut microbial overgrowth, shapes the intestinal bile acid pool, and alleviates inflammation. This narrative review offers a comprehensive summary of the potential of Lactobacillus in the gut-liver axis to attenuate steatosis and MASLD. It also highlights the roles of Lactobacillus in hepatic lipid metabolism, insulin resistance, inflammation and fibrosis, and bile acid synthesis in attenuating MASLD.

Supplementation with Lactiplantibacillus brevis GKEX Combined with Resistance Exercise Training Improves Muscle Mass, Strength Performance, and Body Fat Condition in Healthy Humans

In addition to maintaining good exercise and dietary habits, recent studies have shown that probiotics may have potential benefits for muscle mass and strength. It is worth noting that the effects may vary depending on the specific strains used. To date, no studies have analyzed the effects of Lactiplantibacillus brevis in this context. Here, we combine the L. brevis strain GKEX with resistance training to further understand its effects on muscle mass, thickness, performance, and fat loss. In a six-week intervention for a double-blind randomized trial, 52 healthy subjects were divided into two groups (10 male and 16 female participants in each group): a placebo group (two capsules/day, containing 0 CFU of GKEX per capsule) and a GKEX group (two capsules/day, containing 1 × 1010 CFU of GKEX per capsule). Before the intervention, no differences were observed between the two groups in any of the tests (body composition, muscle thickness, exercise performance, and blood parameters). However, supplementation with GKEX significantly improved muscle mass and thickness, as well as grip strength, muscle strength, and explosive performance, when compared to the associated parameters before the intervention. Additionally, GKEX supplementation promoted a reduction in the body fat percentage (p < 0.05). Through analysis of the change amount, we observed that GKEX supplementation yielded significantly improved benefits when compared to the placebo group (p < 0.05). In summary, our findings support the notion that a six-week resistance exercise training program combined with L. brevis GKEX supplementation has superior additive effects that enhance muscle mass and strength performance, while also reducing body fat percentage. This intervention can promote muscle gain and fat loss.