Correction to: Changes in Circulating Stem and Progenitor Cell Numbers Following Acute Exercise in Healthy Human Subjects: a Systematic Review and Meta-Analysis

The effects of a probiotic mixture (PRO), supplemented with either galacto-oligosaccharide (GOS) or polydextrose (PDX), on cell numbers of lactic acid bacteria (LAB) and bifidobacteria (BIF) were studied in conventional rats and healthy human subjects. In rats the baseline BIF cell numbers were below the detection limit and were increased by the 2-week GOSPRO intervention. In contrast baseline LAB numbers in rats were high and not affected by the treatments. The human study consisted of two independent but concurrent trials; both started with PRO followed by GOSPRO or PDXPRO periods. In the human subjects variation in numbers of BIF and LAB were high. The GOSPRO group exhibited high counts of faecal LAB and BIF at the start and showed little or no effects of the interventions. In contrast, the PDX group had low faecal LAB and BIF numbers at the start and clearly increased cell numbers of BIF after the PDXPRO period, and LAB after the PRO and PDXPRO period, compared with the run-in period. We propose here that responses to pro- and prebiotics are dependent on baseline numbers of LAB and/or BIF, and that the conventional rat model does not predict well the treatment responses in humans. The survival of PRO was presumably enhanced by the use of prebiotic supplementation and advocates the use of particular combinations of pro- and prebiotics.

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The bright and the dark sides of L-carnitine supplementation: a systematic review

Journal of the International Society of Sports Nutrition ◽

10.1186/s12970-020-00377-2 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Angelika K. Sawicka ◽

Gianluca Renzi ◽

Robert A. Olek

Keyword(s):

Systematic Review ◽

Human Subjects ◽

Eligibility Criteria ◽

Healthy Human ◽

Stress Markers ◽

Fasting Plasma ◽

Healthy Human Subjects ◽

Dose Ranging ◽

Total Carnitine

Abstract Background L-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of prolonged LC supplementation on metabolism and metabolic modifications. Methods A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from the inception up February 2020. Eligibility criteria included studies on healthy human subjects, treated for at least 12 weeks with LC administered orally, with no drugs or any other multi-ingredient supplements co-ingestion. Results The initial search retrieved 1024 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with healthy human subjects, with supplemented dose ranging from 1 g to 4 g per day for either 12 or 24 weeks. LC supplementation, in combination with carbohydrates (CHO) effectively elevated total carnitine content in skeletal muscle. Twenty-four-weeks of LC supplementation did not affect muscle strength in healthy aged women, but significantly increased muscle mass, improved physical effort tolerance and cognitive function in centenarians. LC supplementation was also noted to induce an increase of fasting plasma trimethylamine-N-oxide (TMAO) levels, which was not associated with modification of determined inflammatory nor oxidative stress markers. Conclusion Prolonged LC supplementation in specific conditions may affect physical performance. On the other hand, LC supplementation elevates fasting plasma TMAO, compound supposed to be pro-atherogenic. Therefore, additional studies focusing on long-term supplementation and its longitudinal effect on the cardiovascular system are needed.

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