Interplay of Gut Microbiota, Probiotics in Obesity: A Review

Postbiotic heat-killed lactobacilli modulates on body weight associated with gut microbiota in a pig model

For decades, Lactobacillus has been extensively used as beneficial probiotics because it positively effects on the intestinal health of the host and has been studying its possible serve to treat obesity as well as various diseases. This research aimed to investigate the effects of heat-killed Ligilactobacillus salivarius strain 189 (HK LS 189) supplementation on anti-obesity and gut microbiota. A total of 48 pigs were fed either a basal diet or a diet supplemented with HK LS 189 for 4 weeks. The impact of HK LS 189 supplementation on the composition and function of the intestinal microbiota was revealed by 16 S rRNA gene sequencing. HK LS 189 supplementation significantly decreased growth performance. Moreover, HK LS 189 supplementation altered the gut microbiota of the pigs by decreasing the proportion of Prevotella and increasing the proportion of Parabacteroides. Beta-diversity analysis showed a significant difference between the two groups. The results support the potential use of HK LS 189 for its anti-obesity effect in pigs through modulation of the gut microbiota. Furthermore, we found changes in the functional pathways of the gut microbiota. The functional pathway study indicated that metabolism and lipid metabolism differed between the two groups. Our data may contribute to understanding the potential use of postbiotic supplementation with HK LS 189 for improving the anti-obesity effects.

Molecular Study of Lactobacilli Species in Patients with Type 2 Diabetes Mellitus

Background:

Diabetes mellitus type 2 (T2DM) is a metabolic disorder of multiple etiologies due to disturbances in carbohydrate, protein, and fat metabolism. Egypt is among the top 10 countries with a high prevalence of T2DM (15.56% of adults). There are studies that show a link between the diversity of the gut microbiota and the development of T2DM. There are species of Lactobacilli that inhabit the gut that might differ in patients with T2DM compared to healthy subjects.

Objective:

The aim of the present research is to study the presence of Lactobacilli species in gut microbiota by multiplex PCR in patients with T2DM compared to healthy controls as a preliminary approach to open the way for future treatment with the help of probiotics or diet modulation.

Methods:

A retrograde case-control study was conducted on 79 patients with T2DM and 100 healthy controls cross-matched with age and sex. All patients were subjected to full clinical examination and laboratory tests, including identification of stool Lactobacillus species by multiplex polymerase chain reaction (PCR).

Results:

Certain species of L. acidophilus, and L. rhamnosus were found to be significantly increased in patients with T2DM (67.1%, 50.6% respectively) compared to control subjects (35%, P=0.001, OR 3.8, 95% CI:2.1-7.1, 25%, P=0.001, OR 3.1, 95% CI:1.64-5.8 respectively). Other species as determined by multiplex PCR, namely, L. gasseri, (70%, P=0.001, OR 0.16, 95% CI: 0.1-0.3), L. reuteri (74%, P=0.001, OR 0.28, 95% CI: 0.5-0.53), and L. plantarum (69%, P=0.003, OR 0.4, 95% CI: 0.073-0.22) were significantly higher in prevalence in control compared to patients with T2DM.

Conclusion:

The present study highlights the significant prevalence of certain species of Lactobacilli in gut as determined by multiplex PCR, namely L. gasseri, L. reuteri and L. plantarum in controls compared to patients with T2DM. These species may have a role in the reduction of certain risk factors associated with the development of T2DM. Moreover, certain species of L. acidophilus, L. delbrueckii and L. rhamnosus were significantly increased in prevalence in patients with T2DM. The findings of this preliminary study need further verification by a larger longitudinal study.

In vitro evaluation of anticancer effects of different probiotic strains on HCT-116 cell line

AIM

Since the evolution of man, microbes are associated with humans, playing a vital role in the maintenance of good health. However, an imbalance in the gut microbial ecosystem is associated with several diseases including colorectal cancer (CRC). The supplementation with probiotics has been proven to be beneficial in improving CRC. In this study, we have evaluated the anticancer effects of 11 probiotic strains on human colorectal carcinoma cell line (HCT-116).

METHODS AND RESULTS

In this study, HCT-116 cells were treated with various concentrations (0·5, 5, 10, 20 and 200 million CFU per ml) of probiotic strains. The viability was analysed using a MTT assay and IC₅₀ values were determined. Besides this, we evaluated the expression of multiple genes involved in the apoptosis and stress tolerance by real-time PCR. Lactobacillus reuteri (UBLRu-87), Saccharomyces boulardii (Unique-28), Bacillus clausii (UBBC-07), Bacillus coagulans (Unique-IS2), Streptococcus salivarius (UBSS-01), Lactobacillus fermentum (UBLF-31), Lactobacillus salivarius (UBLS-22), Bifidobacterium bifidum (UBBB-55) and Lactobacillus plantarum (UBLP-40) exhibited potent cytotoxicity on HCT 116 cells. Furthermore, UBLF-31 and Unique-28 induced the expression of CJUN, CFOS and CASP-9, and downregulated the expression of BCL6. UBLRu-87 and UBBB-55 induced the expression of CJUN, CFOS and CASP-9 but not BCL-6. UBLP-40, UBBC-07, UBLS-22, and Unique-IS2 induced the expression of CJUN and CASP-9 and downregulated the expression of BCL-6.

CONCLUSION

These studies indicate the anticancer effects of selected probiotic strains by inducing apoptosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

The probiotic strains with the anticancer effects identified in this study can be proposed as potential candidates in the treatment of CRCs.

Lactobacilli spp.: real-time evaluation of biofilm growth

BACKGROUND

Biofilm is a fundamental bacterial survival mode which proceeds through three main generalized phases: adhesion, maturation, and dispersion. Lactobacilli spp. (LB) are critical components of gut and reproductive health and are widely used probiotics. Evaluation of time-dependent mechanisms of biofilm formation is important for understanding of host-microbial interaction and development of therapeutic interventions. Time-dependent LB biofilm growth was studied in two systems: large biofilm output in continuous flow system (microfermenter (M), Institute Pasteur, France) and electrical impedance-based real time label-free cell analyzer (C) (xCELLigence, ACEA Bioscience Inc., San Diego, CA). L. plantarum biofilm growth in M system was video-recorded, followed by analyses using IMARIS software (Bitplane, Oxford Instrument Company, Concord, MA, USA). Additionally, whole genome expression and analyses of attached (A) and dispersed (D) biofilm phases at 24 and 48 h were performed.

RESULTS

The dynamic of biofilm growth of L. plantarum was similar in both systems except for D phases. Comparison of the transcriptome of A and D phases revealed, that 121 transcripts differ between two phases at 24 h. and 35 transcripts - at 48 h. of M growth. The main pathways, down-regulated in A compared to D phases after 24 h. were transcriptional regulation, purine nucleotide biosynthesis, and L-aspartate biosynthesis, and the upregulated pathways were fatty acid and phospholipid metabolism as well as ABC transporters and purine nucleotide biosynthesis. Four LB species differed in the duration and amplitude of attachment phases, while growth phases were similar.

CONCLUSION

LB spp. biofilm growth and propagation area dynamic, time-dependent processes with species-specific and time specific characteristics. The dynamic of LB biofilm growth agrees with published pathophysiological data and points out that real time evaluation is an important tool in understanding growth of microbial communities.

Uso temprano de antibióticos en la infancia y obesidad pediátrica: revisión sistemática de la literatura

Introducción: la prevalencia de obesidad en el mundo es creciente y específicamente la obesidad en niños se ha convertido en un problema de salud pública que preocupa a varios países. La evidencia ha señalado al uso de antibióticos en la infancia como un factor relacionado con la presencia de obesidad infantil.Objetivo: Analizar sistemáticamente la evidencia reciente acerca de la relación entre el uso temprano de antibióticos en la infancia y la presencia de obesidad infantil.Métodos: Se realizó una búsqueda bibliográfica en las bases de Pubmed, Ovid, EBSCO, Lilacs, JAMA pediatrics de estudios observacionales en los últimos diez años que abordaran la relación entre el uso de antibióticos antes de los 24 meses de edad y la obesidad infantil.Resultados: Luego de realizar el tamizaje de los artículos, se seleccionaron 9 para la síntesis cualitativa. Con dos excepciones, los estudios analizados muestran una relación estadísticamente significativa entre el uso temprano de antibióticos y la obesidad o sobrepeso infantil, medido como peso para la edad o mediante el índice de masa corporal y aún con el ajuste por las potenciales variables de confusión, esta asociación permanece siendo estadísticamente significativa, debido a algunos de los diseños epidemiológicos, no se puede verificar la relación de antecedencia temporal de la exposición. 

Probiotics: How Effective Are They in the Fight against Obesity?

Obesity has been associated with structural and functional changes in the gut microbiota. The abundance in, and diversity of, certain bacteria may favor energy harvest and metabolic pathways leading to obesity. Therefore, gut microbiota has become a potential target that can be manipulated to obtain optimal health. Probiotics have been shown to influence the composition of the gut microbiota, improve gut integrity, and restore the microbial shifts characteristic of obesity. Based on physical and biochemical parameters, metabolic and inflammatory markers, and alterations in gut microbe diversity, animal studies revealed beneficial results in obese models whereas the results in humans are sparse and inconsistent. Thus, the purpose of this review is to present evidence from animal studies and human clinical trials demonstrating the effects of various probiotic strains and their potential efficacy in improving obesity and associated metabolic dysfunctions. Furthermore, the review discusses current gaps in our understanding of how probiotics modulate gut microflora to protect against obesity. Finally, we propose future studies and methodological approaches that may shed light on the challenges facing the scientific community in deciphering the host–bacteria interaction in obesity.

RS, Sharma RK, Pothuraju R, Mohanty AK. Ameliorative effect of fermentable fibres on adiposity and insulin resistance in C57BL/6 mice fed a high-fat and sucrose diet

The consumption of diets rich in fat and refined sugars is recognized to be one of the causes of lifestyle disorders, and dietary fibres are being advocated to ameliorate the complications associated with these disorders.

Links between the circadian rhythm, obesity and the microbiome

Obesity is linked to a wide range of serious illnesses. In addition to the important impact on the health of the individual, obesity also has a substantial impact on the economy. Disruption of physiological day-night cycles could contribute to the increased incidence of obesity. According to the American National Sleep Federation, the percentage of the people who reported a sleep duration of six hours or less increased from 12 to 37 % over ten years. Insufficient sleep leads not only to an increase of the total calorie intake but changes the meal preference in favor of palatable foods and meals with high carbohydrate content. A decrease of leptin and increase of ghrelin levels caused by sleep deficiency can also play a role. In addition to the higher caloric intake, the timing of food consumption should be taken into account. The same meal eaten during the night versus the day is associated with increased postprandial glucose and triglyceride levels. The gut microbiome has also been recently understood as an endocrine system, with links between the gut microbiome and circadian rhythm changes possibly influencing increased obesity.

Diet induced maternal obesity affects offspring gut microbiota and persists into young adulthood

Accumulating evidence suggests that diet could shape the host gut microbiome composition. Herein, we investigated the effects of maternal high fat diet (HFD) consumption on the gut microbiota and serum profile of mice offspring, and attempted to explore the beneficial roles of maternal probiotics intervention. Female C57BL/6J mice were fed with normal diet, HFD or HFD with daily probiotics (B. breve DM8310, L. acidophilus DM8302, L. casei DM8121 and S. thermophilus DM8309) by gavage starting 6 weeks prior to breeding and continued throughout gestation and lactation. Pups of HFD dams had higher levels of total cholesterol (TC), low-density lipoprotein (LDL), glucose, insulin and leptin compared to those of chow-fed dams. Maternal probiotics intervention resulted in a decrease in the lipid levels in all the pups, while the glucose, insulin and leptin levels were decreased only in adult female pups compared to those from HFD-fed dams; the decreased levels were similar to those in the pups of chow-fed dams. In line with these plasma changes, maternal HFD persistently altered the composition of the offspring gut microbiota in a sex specific way. Maternal probiotics intervention could ameliorate gut microbiota dysbiosis in the offspring. Such intervention showed better effects particularly for the female pups at adulthood. In conclusion, maternal HFD-induced gut microbiota dysbiosis and metabolic disorder could persist through the adulthood of the offspring. Maternal probiotics intervention can negate the detrimental effects of maternal HFD on the gut microbiota and metabolism in the offspring in a sex specific way.