Sarcopenia, the age-related decline in muscle mass and strength, is a contributor to frailty and reduced quality of life. Emerging evidence suggests an emerging role of the gut microbiome in modulating skeletal muscle through microbial species and metabolites, such as short-chain fatty acids (SCFAs), potentially influencing inflammation, nutrient absorption, and glucose and protein metabolism. This review considers the potential of probiotics, prebiotics, and synbiotics as interventions to mitigate sarcopenia based on animal and human studies, while providing a critique of present barriers that need to be addressed. Preclinical models, including germ-free mice and faecal microbiota transplantation, demonstrate that gut microbiota from healthy or young donors may enhance overall muscle health via reductions in inflammatory and muscle atrophy markers. Limited human studies show that probiotics such as Lactobacillus and Bifidobacterium could improve branched-chain amino acid (BCAA) bioavailability and potentially sarcopenia indices, although findings have been inconsistent. Particularly, challenges including inconsistent microbial assessments, lack of dietary control and interindividual variability due to diet, age, genetics, comorbidities and medications may hinder progress in this field. Delivery methods (e.g. capsules, fermented foods or fortified products) could further complicate efficacy through probiotic stability and dietary restrictions in older adults. Standardised protocols [e.g. Strengthening The Organisation and Reporting of Microbiome Studies (STORMS) checklist] and multi-omics approaches may be critical to address these limitations and identify microbial signatures linked to sarcopenia outcomes. While preclinical evidence highlights mechanistic pathways pertinent to amino acid metabolism, translating findings to humans requires rigorous experimental trials.

Although many online-based dietary surveys have been developed in recent years, systems that easily survey the dietary balance based on the Japanese diet are insufficient. This study aimed to evaluate the relationship between dietary balance scores from an online survey system based on the Japanese Food Guide Spinning Top, and nutrient/food intake calculated using the weighing method from dietary records (DRs), as well as to assess the system’s utility and applicability. An online dietary balance survey and semi-weighted DR assessment with food photographs were conducted in Japanese participants (n = 34). Registered dietitians entered the balance scores into the system based on the participants’ food photographs, and the scores were calculated using the system. Significant positive correlations (p < 0.001) were found between the online dietary balance scores and nutrient/food intake from DRs; especially for ‘grain dishes’ and carbohydrates (r = 0.704); ‘vegetable dishes’ and the vegetable dish group (sum of potatoes, vegetables, mushrooms, and algae) (r = 0.774); ‘main dishes’ and protein (r = 0.661); ‘milk’ and the milk and milk products group (r = 0.744); and ‘fruits’ and the fruits group (r = 0.748). Bland–Altman analysis showed that the dietary balance scores obtained by this system tended to underestimate the intake compared with the weighing method. Although there are limitations to the accurate estimation of nutrient and food intake, the online dietary balance scores obtained from the online dietary balance survey system were useful for understanding the dietary balance in the Japanese diet.

Kids SIPsmartER is a school-based behavioural intervention for rural Appalachia middle school students with an integrated two-way short message service (SMS) strategy for caregivers. When tested in a cluster randomized controlled trial, the intervention led to significant improvements in sugar-sweetened beverage (SSB) consumption among students and caregivers. This study explores changes in secondary caregiver outcomes, including changes in caregiver SSB-related theory of planned behaviour constructs (affective attitudes, instrumental attitudes, subjective norms, perceived behavioural control, and intentions), parenting practices, and the home environment. Participants included 220 caregivers (93% female, 88% White, 95% non-Hispanic, mean age 40.6) in Virginia and West Virginia at baseline and 7 months post-intervention. Relative to control caregivers (n = 102), intervention caregivers (n = 118) showed statistically significant improvements in instrumental attitudes (Coef.= 0.53, 95% CI [0.04, 1.01], p = 0.033), behavioural intentions (Coef.=0.46, 95% CI [0.05, 0.88], p = 0.027), parenting practices (Coef. = 0.22, 95% CI [0.11, 0.33], p < 0.001), and total home SSB availability (Coef. = –0.25, 95% CI [–0.39, –0.11], p < 0.001), with specific improvements for sweetened juice drinks (Coef. = –0.18, 95% CI [–0.35, –0.01], p = 0.043) and regular soda/soft drinks (Coef. = –0.31, 95% CI [–0.55, –0.07], p = 0.010). In contrast, there were no significant between group changes for affective attitudes, subjective norms, or perceived behavioural control. Our findings highlight future research areas and fill gaps in intervention literature. This study is among the few to develop and evaluate a scalable, theory-based caregiver SMS component in a rural, school-based intervention. Combined with evidence that Kids SIPsmartER improved SSB behaviours, our results emphasize the potential of theory-guided SMS interventions to impact SSB-related outcomes.

Trial registration: Clincialtrials.gov: NCT03740113.

Despite the multiple advantages of 25-hydroxyvitamin D (calcifediol or 25(OH)D) compared to cholecalciferol, it is used sparingly. This study was planned to assess the safety and efficacy of supplementing daily 25 µg of calcifediol capsules vis-a-vis 100 µg (4000 IU) of cholecalciferol sachets in apparently healthy individuals with vitamin D deficiency in Chandigarh, India (latitude 30.7° North, 76.8° East). It was a prospective, interventional study to evaluate the effects of calcifediol vis-a-vis cholecalciferol. Following initial screening of 70 subjects in each group, 62 were included in the calcifediol and 41 in the cholecalciferol group. Forty-six from calcifediol and 37 from cholecalciferol group completed the 6-month follow up. There was a significant increase in serum 25(OH)D (355% in cholecalciferol & 574% in calcifediol groups, respectively, p < 0.001) and 1,25 (OH)2D (p < 0.001) with a marked decrease in iPTH (p < 0.001) and ALP (p = 0.016) in both groups. Though serum ALP decreased significantly more in the calcifediol group than the cholecalciferol group, no appreciable difference in other biochemical parameters was noted between the groups. No episodes of hypercalcaemia or incidence of new renal stone disease were observed during follow-up. However, hypercalciuria (spot urine calcium creatinine > 0.2 mg/mg) was noted in 8/46 individuals in the calcifediol group and 5/37 individuals in the cholecalciferol group at final visit with no significant difference between two groups. This study establishes the efficacy and safety of correcting vitamin D deficiency with daily 25 µg calcifediol capsules as an alternative to 4000 IU (100 µg) cholecalciferol sachets.