L-carnitine and synbiotic co-supplementation could help combat obesity in women

Obesity, a global health crisis driven by complex interplays of behaviour, environment and genetics, has reached pandemic proportions, demanding effective therapeutic interventions. While lifestyle modifications and dietary changes remain primary strategies for weight reduction, adherence to these programmes has proven challenging for many individuals.

At the same time, anti-obesity medications are typically prescribed as part of a comprehensive weight management plan. Some common medications may include orlistat, liraglutide, buopropion / naltrexone and phentermine / topiramate. However, these have led to side effects in some patients.

For instance, orlistat, which works by preventing the absorption of dietary fat, may cause gastrointestinal issues like oily stools, flatulence and abdominal cramps. Liraglutide, which was originally developed for diabetes management, may result in nausea, vomiting and diarrhoea.

Consumption of the appetite suppressant phentermine may lead to increased heart rate, insomnia and dry mouth. Phentermine is sometimes also combined with the anti-epileptic drug topiramate; the side effects of this combination may include nausea, constipation, and headaches. Obese individuals are also sometimes prescribed a combination of the anti-depressant bupropion and the anti-addiction drug naltrexone, with some having reported nausea, constipation and headaches after taking it.

In light of the drawbacks associated with anti-obesity medications, the consumption of weight loss supplements — particularly nutraceuticals and functional foods —has gained popularity as adjuvant therapies.

A novel approach to fat-fighting​

Based on this, researchers at the Tabriz University of Medical Sciences conducted a clinical trial to shed light on the promising combination of L-carnitine (a key player in glucose and lipid metabolism) and synbiotics that target gut microbiota dysbiosis as a formidable approach to tackle obesity and related cardio-metabolic complications.

L-carnitine, which is often available over-the-counter, is known for its potential anti-obesity, anti-diabetic and lipid-improving effects. It is said to enhance fatty acid beta-oxidation, increases energy expenditure and modulates gene expression in adipocytes. Multi-strain synbiotics, in particular, have been highlighted as more effective in modulating gut microbiota compared to single-strain synbiotics or individual probiotic or prebiotic therapies.

The researchers also emphasised the critical role of gut microbiota dysbiosis in obesity, prompting the evaluation of microbiota-remodelling strategies such as pro-, pre- or synbiotic therapy. Synbiotics, a combination of probiotics and prebiotics, have shown weight-reducing effects in various meta-analyses and demonstrated improved lipid profiles and insulin sensitivity.

The clinical trial, which involved 46 women with obesity, examined the effects of L-carnitine single therapy compared to L-carnitine and multi-strain synbiotic co-supplementation over an eight-week period. Both interventions showed significant improvements in anthropometric, lipid and glycaemic indices.

However, the group supplemented with a combination of L-carnitine and synbiotic exhibited greater reductions in body mass index (BMI), body weight and various circumferences, along with improved glycaemic parameters.

Based on this, the researchers drew attention to the potential benefits of combining L-carnitine with other pharmaceutical or nutraceutical therapies, suggesting synergistic effects in addressing weight, glycaemic or lipid profiles.

Compelling conclusion​

The findings of the study underscored the potential synergy between L-carnitine and synbiotics in simultaneously targeting diverse metabolic pathways, leading to more pronounced effects on weight and metabolic parameters. It also suggested that this combined approach could serve as a promising and rational strategy to alleviate obesity and associated complications.

While acknowledging the strengths of the study, such as participant criteria, low drop-out rates and high adherence, the researchers also acknowledged limitations, including the relatively short intervention duration and the absence of a third intervention group receiving synbiotics alongside a placebo.

The study presented compelling evidence for the synergistic or complementary effects of L-carnitine and synbiotics in combating obesity and cardio-metabolic complications, paving the way for further investigations into the underlying mechanisms and potential therapeutic applications of this form of supplementation.

The researchers concluded: “Our findings suggest that co-administration of L-carnitine and synbiotic may be an encouraging therapeutic strategy for obesity and related cardiometabolic complications, possibly due to simultaneous targeting of multiple metabolic pathways, augmenting their bio-availability / function through potential complementary or synergistic mechanisms.

“Moreover, co-encapsulation of synbiotics and L-carnitine as a single micro-capsule could be considered as a conceivable delivery system to enhance the stability and efficacy of synbiotics, as well as to reduce the cost of the final product. Further mechanistic investigations are warranted to clarify the exact mechanisms mediating the synergistic effect of L-carnitine and synbiotic combined therapy on weight and metabolic parameters.”

Source: Frontiers in Endocrinology​

“Ameliorating effects of L-carnitine and synbiotic co-supplementation on anthropometric measures and cardiometabolic traits in women with obesity: a randomized controlled clinical trial”​

https://doi.org/10.3389/fendo.2023.1237882​

Authors: Farnoush Fallah, et al​.