The relationship between diet and the diversity and function of the intestinal microbiome and its importance for human health is currently the subject of many studies. The type and proportion of microorganisms found in the intestines can determine the energy balance of the host. Intestinal microorganisms perform many important functions, one of which is participation in metabolic processes, e.g., in the production of short-chain fatty acids—SCFAs (also called volatile fatty acids). These acids represent the main carbon flow from the diet to the host microbiome. Maintaining intestinal balance is necessary to maintain the host’s normal health and prevent many diseases. The results of many studies confirm the beneficial effect of probiotic microorganisms on the balance of the intestinal microbiome and produced metabolites, including SCFAs. The aim of this review is to summarize what is known on the effects of probiotics on the production of short-chain fatty acids by gut microbes. In addition, the mechanism of formation and properties of these metabolites is discussed and verified test results confirming the effectiveness of probiotics in human nutrition by modulating SCFAs production by intestinal microbiome is presented.

The Effect of Probiotics on the Production of Short-Chain Fatty Acids by Human Intestinal Microbiome.

Potential mechanisms underlying the ameliorative effect of Lactobacillus paracasei FZU103 on the lipid metabolism in hyperlipidemic mice fed a high-fat diet.

Lactobacillus fermentum CECT5716 ameliorates high fat diet-induced obesity in mice through modulation of gut microbiota dysbiosis.

Weissella strains have been the subject of much research over the last 5 years because of the genus' technological and probiotic potential. Certain strains have attracted the attention of the pharmaceutical, medical, and food industries because of their ability to produce antimicrobial exopolysaccharides (EPSs). Moreover, Weissella strains are able to keep foodborne pathogens in check because of the bacteriocins, hydrogen peroxide, and organic acids they can produce; all listed have recognized pathogen inhibitory activities. The Weissella genus has also shown potential for treating atopic dermatitis and certain cancers. W. cibaria, W. confusa, and W. paramesenteroides are particularly of note because of their probiotic potential (fermentation of prebiotic fibers) and their ability to survive in the gastrointestinal tract. It is important to note that most of the Weissella strains with these health-promoting properties have been shown to be save safe, due to the absence or the low occurrence of virulence or antibiotic-resistant genes. A large number of scientific studies continue to report on and to support the use of Weissella strains in the food and pharmaceutical industries. This review provides an overview of these studies and draws conclusions for future uses of this rich and previously unexplored genus.

Weissella: An Emerging Bacterium with Promising Health Benefits.

The effects of a submerged fermentation with a mixed inoculum composed of potentially probiotic Lactobacillus isolates, namely L. casei L-26, L. fermentum 56, L. paracasei 106 and L. plantarum 53, on physicochemical characteristics, bioactive compounds and antioxidant activity of acerola (ACE) and guava (GUA) fruit industrial by-products were measured. Viable counts of probiotic lactobacilli in ACE and GUA after a 120 h-fermentation were of ≥5.5 log CFU/mL. Fermented ACE and GUA had increased luminosity and decreased contrast. Contents of total soluble solids and pH decreased and titrable acidity increased in ACE and GUA during fermentation. Ascorbic acid contents decreased in ACE and increased in GUA during fermentation. Different phenolic compounds were found in ACE and GUA during fermentation. Fermented ACE and GUA had increased contents of total flavonoids and total phenolics and antioxidant activity. Contents of total flavonoids and total phenolics were correlated with antioxidant activity in fermented ACE and GUA. These results indicate that submerged fermentation with probiotic lactobacilli could be a strategy to improve the contents of bioactive compounds and antioxidant activity of ACE and GUA.

Improvement in physicochemical characteristics, bioactive compounds and antioxidant activity of acerola (Malpighia emarginata D.C.) and guava (Psidium guajava L.) fruit by-products fermented with potentially probiotic lactobacilli

Background and aim High-fat (HF) diet consumption has been associated with gut dysbiosis and increased risk of dyslipidemia, type 2 diabetes mellitus and hypertension. Probiotic administration has been suggested as a safe therapeutic strategy for the treatment of cardiometabolic disorders. This study was designed to assess the effects of probiotic Lactobacillus (L.) fermentum 296, a fruit-derived bacteria strain, against cardiometabolic disorders induced by HF diet. Methods and results Male Wistar rats were divided into control diet (CTL); HF diet; and HF diet treated with Lactobacillus fermentum 296 (HF + Lf 296). The L. fermentum 296 strain at 1 × 109 colony forming units (CFU)/ml were daily administered by oral gavage for 4 weeks. The results showed that rats fed with HF diet displayed insulin resistance, reduced Lactobacillus spp. counts in feces, serum lipids, and oxidative profile. Rats fed on HF diet also demonstrated augmented blood pressure associated with sympathetic hyperactivity and impaired baroreflex control. The administration of L. fermentum 296 for 4 weeks recovered fecal Lactobacillus sp. counts and alleviated hyperlipidemia, sympathetic hyperactivity, and reduced systolic blood pressure in HF rats without affecting baroreflex sensibility. Conclusion Our results suggest the ability of L. fermentum 296 improve biochemical and cardiovascular parameters altered in cardiometabolic disorders.

The probiotic Lactobacillus fermentum 296 attenuates cardiometabolic disorders in high fat diet-treated rats.

Maternal dyslipidaemia is a predisposing factor for arterial hypertension in male rat offspring at adulthood. This study was designed to investigate the short- and long-term effects of maternal dyslipidaemia on blood pressure (BP) and baroreflex control in male rat offspring. Animals were obtained from mothers who received a dyslipidaemic (DLP, n = 7) or control (CTL, n = 7) diet during pregnancy and lactation. At 30 and 90 days of age, arterial pressure (AP), heart rate (HR) and baroreflex function were evaluated. In addition, spectral analysis of the systolic AP, diastolic AP, mean AP, HR, and spontaneous baroreflex were assessed. Data were expressed as mean ± SEM and Student's t-test was used for comparison among groups, with statistical significance considered to be P < .05. At 30 days of age, male offspring had similar BP, HR and preserved baroreflex sensitivity. In addition, low frequency (LF) oscillation, high frequency (HF) oscillation and LF/HF ratio of AP and HR were similar in juvenile rats. At 90 days of age, male offspring from dyslipidaemic dams had augmented BP (P < .05) when compared to CTL group. Adult male rats from dyslipidaemic dams had a reduction in baroreflex control (P < .05) in comparison to CTL rats. The present study indicates that offspring from dams fed on a dyslipidaemic diet during pregnancy and lactation do not show alteration in blood pressure and baroreflex control in early life, but display a decline in baroreflex control and hypertension in adulthood.

Short- and long-term effects of maternal dyslipidaemia on blood pressure and baroreflex sensitivity in male rat offspring.

Oxidative stress, inflammation, and gut microbiota impairments have been implicated in the development and maintenance of diabetes mellitus. Strategies capable of recovering the community of commensal gut microbiota and controlling diabetes mellitus have increased in recent years. Some lactobacilli strains have an antioxidant and anti-inflammatory system capable of protecting against oxidative stress, inflammation, and diabetes mellitus. Experimental studies and some clinical trials have demonstrated that Limosilactobacillus fermentum strains can beneficially modulate the host antioxidant and anti-inflammatory system, resulting in the amelioration of glucose homeostasis in diabetic conditions. This review presents and discusses the currently available studies on the identification of Limosilactobacillus fermentum strains with anti-diabetic properties, their sources, range of dosage, and the intervention time in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of Limosilactobacillus fermentum strains capable of inducing anti-diabetic effects and promoting health benefits.

Lucas Alves Carneiro dos Santos

Papers

The probiotic Lactobacillus fermentum 296 attenuates cardiometabolic disorders in high fat diet-treated rats.

Short- and long-term effects of maternal dyslipidaemia on blood pressure and baroreflex sensitivity in male rat offspring.

Potential role of Limosilactobacillus fermentum as a probiotic with anti-diabetic properties: A review