The probiotic did not have arm-wide effects in metabolic syndrome or immune parameters but divided the probiotic arm into responders and non-responders
metabolic syndrome
METABOLIC SYNDROME, INFLAMMATION
The primary outcome of change in metabolic syndrome parameters in participants with metabolic syndrome (including only the 21 participants from the probiotic arm that had at least three parameters above the IDF guidelines and all 13 placebo arm participants) from beginning (week 0) to end (week 10) of intervention was not significant in the probiotic arm (MetSyn parameters did not improve in the probiotic arm, but participants cluster into responder and non-responder groups. (A) MetSyn parameters and (B) alanine aminotransferase (ALT), insulin, and LDL cholesterol at baseline (“B”, week 0) and end of intervention (“W10”, week 10) for probiotic (n=21; participants that had at least 3 elevated parameters and thus met the definition of metabolic syndrome) and placebo arms (n=13). (C) Change from baseline average (weeks -4, -2, 0) to end of intervention (weeks 8, 10) for each participant in placebo, probiotic responder (R), or probiotic non-responder (NR) groups. All probiotic participants (n=26) plotted including those with only 2 elevated parameters (‪ indicates participants that only satisfied 2 criteria for MetSyn). Each row is a participant and is hierarchically clustered by parameters shown. § indicates significant difference between average baseline and end of intervention within the probiotic responders (paired t-test < 0.05). ‡ indicates significant difference between average percent fold change between probiotic responders and placebo (unpaired t-test < 0.05). † indicates significant difference between average baseline and end of intervention within the probiotic non-responders (paired t-test < 0.05). # indicates significant difference between average percent fold change between probiotic non-responders and placebo (unpaired t-test <0.05). (D) Principal coordinate analysis of Euclidean distances for % change in inflammatory marker from baseline (week -3) to end of intervention (week 10) for all participants. Circles denote 50% confidence level for a multivariate t-distribution. (E) Change in serum homovanillic acid levels from baseline (week -3) to end of intervention (week 10) for placebo, probiotic non-responders (NR), and responders (R) (unpaired t-test, post-hoc p-value = 0.004).We next leveraged aspects of our study design (e.g., the longitudinal sampling, dietary records, ability to perform microbiome profiling) in a discovery analysis process to reveal trends that could inform possible probiotic efficacy and hypotheses for future studies.Unlike the probiotic arm, the placebo arm did not separate into clear groupings, with the 13 participants most naturally splitting into four groups one of which only contained a single participant (In summary, the probiotic treatment did not reduce parameters of metabolic syndrome as a whole. However, a subset of participants, the probiotic responders, did exhibit decreases in triglycerides and diastolic blood pressure over the course of the intervention with the decrease in triglycerides significant relative to the placebo group. The probiotic non-responders increased blood glucose and insulin levels over time, with the increase in glucose significant relative to the placebo group. These data are consistent with some participants improving with probiotic supplementation and others faring worse relative to no probiotic intervention.While there were not cohort-wide improvements in metabolic syndrome parameters in the probiotic arm relative to placebo, we wondered whether there were observable changes in aspects of participants’ immune system in response to the probiotic. Increased inflammation, as determined by elevated levels of several circulating pro-inflammatory cytokines and chemokines, has been linked to metabolic syndrome.We next wondered whether the probiotic affected circulating metabolites, many of which serve as markers of physiological and metabolic processes in humans. We ran untargeted metabolomics using our recently reported high-throughput liquid chromatography-mass spectrometry (LC-MS) approach