Microbial metabolites PAS and casted muscle in aged mice: sex-dependent effects
In aged mice with one hindlimb casted for 10 days, drinking-water PAS did not preserve soleus or plantaris mass, but casted gastrocnemius mass was greater than with vehicle; fiber-size and function effects differed by sex. [1]
Automatic summary · not editorially reviewed
The key findings
Aged male and female mice received vehicle or PAS in drinking water during 10 days of unilateral hindlimb casting. [1]
PAS did not preserve soleus or plantaris mass, but casted gastrocnemius mass was greater than with vehicle regardless of sex. [1]
Soleus contractile function improved sex-specifically: females greater absolute force and rate of force development, males greater fatigue resistance. [1]
The source at a glance
- Study type / format
- Preclinical mouse study (abstract)
- Population / context
- Aged male and female mice undergoing 10 days of unilateral hindlimb casting.
- Summary based on
- Study abstract
- Original publication
- October 1, 2026
Aged mice, 10-day casting, PAS versus vehicle in water
The abstract describes aged male and female mice given either vehicle or PAS (pipecolic acid and succinate, microbial-derived exerkines) in drinking water during 10 days of unilateral hindlimb casting. The question was whether PAS, which previously prevented disuse-induced atrophy and preserved muscle function in adult mice, similarly protects aged muscle. This is an abstract of a mouse study; the full text was not reviewed.
Supporting source [1]
Muscle mass, fiber size and function in casted limbs
PAS did not preserve soleus or plantaris mass. Casted gastrocnemius mass was greater in PAS- than vehicle-treated mice irrespective of sex. PAS attenuated the loss of soleus and plantaris fiber cross-sectional area, with the largest effect in the female soleus. Soleus contractile function improved in a sex-specific way: females showed greater absolute force and rate of force development, males greater fatigue resistance. Gastrocnemius citrate synthase activity was greater in PAS- than vehicle-treated females but not males.
Supporting source [1]
Sex differences and limits of this mouse abstract
The authors describe sexually dimorphic responses and present microbial-derived metabolites as a possible therapeutic avenue for preserving muscle function during disuse in aging, while stressing sex as a biological variable. These are findings in aged mice, not evidence of benefit in people, and associations in this design do not establish causes. The abstract reports no sample sizes, no follow-up beyond the 10-day casting period and no human data; the full text was not reviewed.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. Mouse study with no reported sample sizes, no follow-up beyond 10 days of casting and no human data. Findings do not establish causes or benefits for people.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Daredia J, Valentino TR, Ismaeel A, Wen Y, McCarthy JJ, Burke BI. · europepmc.org · October 1, 2026