Supplementation with Combined Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 Across Development Reveals Sex Differences in Physiological and Behavioural Effects of Western Diet in Long-Evans Rats

Co-culturing Bifidobacterium animalis ssp. lactis with Lactobacillus helveticus accelerates its growth and fermentation in milk through metabolic interactions

This study aimed to investigate the interaction between Lactobacillus helveticus H9 (H9) and Bifidobacterium animalis ssp. lactis Probio-M8 (M8) through metabolomics analysis, focusing on understanding how co-culturing these strains can enhance bacterial growth and metabolism, thereby shortening the fermentation cycle and improving efficiency. The H9 and M8 strains were cultured individually and in combination (1:1 ratio) in milk. The fermented milk metabolomes were analyzed using solid-phase microextraction-gas chromatography-mass spectrometry. In the dual-strain fermentation, the M8 strain exhibited a 2.33-fold increase in viable bacterial count compared with single-strain fermentation. Additionally, the dual-strain fermentation resulted in greater metabolite abundance and diversity. Notably, the dual-strain fermented milk showed significantly elevated levels of metabolites, including 5-methyl-2-hexanone, (E)-3-octen-2-one, acetic acid, alanine, and 3-hydroxy-butanal. Our results demonstrated that co-culturing the M8 and H9 strains accelerated growth and fermentation efficiency. This enhancement effect is likely attributed to the strong proteolytic ability of the H9 strain, which hydrolyzes casein to produce small molecular peptides, alanine, tyrosine, and other growth-promoting factors. The insights gained from this study have significant implications for probiotics and the dairy industry, potentially leading to shorter fermentation cycles, enhanced cost-effectiveness, and improved nutritional and functional properties of future fermented milk products. Additionally, these findings may contribute to advancements in probiotic research and applications.

Probiotics and eating disorders: a systematic review of humans and animal model studies

BACKGROUND

Eating disorders are complex mental health conditions that significantly impact physical and mental well-being. Current research suggests a potential link between eating disorders and the gut microbiota, highlighting the role of gut-brain communication and its influence on nutrient absorption. Probiotics, which are beneficial bacteria, have shown promise in modulating the gut microbiota and may offer complementary interventions in the treatment of eating disorders.

METHODS

A comprehensive search was conducted in electronic databases, including PubMed/Medline, Scopus, and Web of Science, from inception to January 2024 to analyze the existing literature on the effects of probiotic supplementation in eating disorders. The search strategy included terms related to probiotics, prebiotics, eating disorders, and food addiction. The human studies were assessed for risk of bias using the Cochrane tool. The quality of animal studies was evaluated using the risk of bias (RoB) tool from the Systematic Review Centre for Laboratory Animal Experimentation.

RESULTS

Of the 417 papers, 12 eligible studies were included comprising five animal and seven clinical studies. Clinical trials ranged from 10 to 20 weeks and were randomized and parallel-arm design. The included studies varied in terms of sample characteristics, intervention types, and outcome measures. Preliminary findings suggest that probiotics may influence gut microbiota composition and may offer support in the treatment of eating disorders.

CONCLUSIONS

The reviewed studies showed that probiotic supplementation may have a role in reducing food addiction and binge eating, and enhancing satiety, regulating food intake as well as positively affecting mood. However, further studies with better quality and larger sample size are needed to further validate these findings.

Metabolic Status Influences Probiotic Efficacy for Depression-PRO-DEMET Randomized Clinical Trial Results

Probiotics may represent a safe and easy-to-use treatment option for depression or its metabolic comorbidities. However, it is not known whether metabolic features can influence the efficacy of probiotics treatments for depression. This trial involved a parallel-group, prospective, randomized, double-blind, controlled design. In total, 116 participants with depression received a probiotic preparation containing Lactobacillus helveticus Rosell®-52 and Bifidobacterium longum Rosell®-175 or placebo over 60 days. The psychometric data were assessed longitudinally at five time-points. Data for blood pressure, body weight, waist circumference, complete blood count, serum levels of C-reactive protein, cholesterol, triglycerides, and fasting glucose were measured at the beginning of the intervention period. There was no advantage of probiotics usage over placebo in the depression score overall (PRO vs. PLC: F(1.92) = 0.58; p = 0.45). However, we found a higher rate of minimum clinically important differences in patients supplemented with probiotics than those allocated to placebo generally (74.5 vs. 53.5%; X2(1,n = 94) = 4.53; p = 0.03; NNT = 4.03), as well as in the antidepressant-treated subgroup. Moreover, we found that the more advanced the pre-intervention metabolic abnormalities (such as overweight, excessive central adipose tissue, and liver steatosis), the lower the improvements in psychometric scores. A higher baseline stress level was correlated with better improvements. The current probiotic formulations may only be used as complementary treatments for depressive disorders. Metabolic abnormalities may require more complex treatments. ClinicalTrials.gov identifier: NCT04756544.

Bifidobacteria in disease: from head to toe

Bifidobacteria as a strictly anaerobic gram-positive bacteria, is widely distributed in the intestine, vagina and oral cavity, and is one of the first gut flora to colonize the early stages of life. Intestinal flora is closely related to health, and dysbiosis of intestinal flora, especially Bifidobacteria, has been found in a variety of diseases. Numerous studies have shown that in addition to maintaining intestinal homeostasis, Bifidobacteria may be involved in diseases covering all parts of the body, including the nervous system, respiratory system, genitourinary system and so on. This review collects evidence for the variation of Bifidobacteria in typical diseases among various systems, provides mild and effective therapeutic options for those diseases that are difficult to cure, and moves Bifidobacteria from basic research to further clinical applications.

Probiotics therapy show significant improvement in obesity and neurobehavioral disorders symptoms

Obesity is a complex metabolic disease, with cognitive impairment being an essential complication. Gut microbiota differs markedly between individuals with and without obesity. The microbial-gut-brain axis is an important pathway through which metabolic factors, such as obesity, affect the brain. Probiotics have been shown to alleviate symptoms associated with obesity and neurobehavioral disorders. In this review, we evaluated previously published studies on the effectiveness of probiotic interventions in reducing cognitive impairment, depression, and anxiety associated with obesity or a high-fat diet. Most of the probiotics studied have beneficial health effects on obesity-induced cognitive impairment and anxiety. They positively affect immune regulation, the hypothalamic-pituitary-adrenal axis, hippocampal function, intestinal mucosa protection, and glucolipid metabolism regulation. Probiotics can influence changes in the composition of the gut microbiota and the ratio between various flora. However, probiotics should be used with caution, particularly in healthy individuals. Future research should further explore the mechanisms underlying the gut-brain axis, obesity, and cognitive function while overcoming the significant variation in study design and high risk of bias in the current evidence.

Gut Microbiota–Brain Axis in Regulation of Feeding Behavior

The survival of microorganisms inhabiting the intestinal tract depends on the nutrients provided by the host, with the latter obtaining them through food intake. It is hence not surprising that the co-evolution of gut bacteria and their hosts, including humans, shaped intrinsic interactions between their respective metabolisms with an impact on host feeding behavior. Understanding molecular pathways underlying such interactions may aid in the development of new therapeutic approaches for several pathological conditions accompanied by altered feeding behavior. A Special Issue titled “Gut Microbiota–Brain Axis in Regulation of Feeding Behavior” contributes to this topic of research, with eight papers covering its various aspects such as autoprobiotics, metabolic diseases and anorexia.

The effect of probiotics on immune responses and their therapeutic application: A new treatment option for multiple sclerosis

Multiple sclerosis (MS) is known as a chronic inflammatory disease (CID) that affects the central nervous system and leads to nerve demyelination. However, the exact cause of MS is unknown, but immune system regulation and inhibiting the function of inflammatory pathways may have a beneficial effect on controlling and improving the disease. Studies show that probiotics can alter the gut microbiome, thereby improving and affecting the immune system and inflammatory responses in patients with MS. The results show that probiotics have a good effect on the recovery of patients with MS in humans and animals. The present study investigated the effect of probiotics and possible therapeutic mechanisms of probiotics on immune cells and inflammatory cytokines. This review article showed that probiotics could improve immune cells and inflammatory cytokines in patients with MS and can play an effective role in disease management and control.

A comparative study of Western, high-carbohydrate, and standard lab diet consumption throughout adolescence on metabolic and anxiety-related outcomes in young adult male and female Long-Evans rats

Anxiety and obesity are prevalent health concerns that are affected by diet in rodents and humans. How diet influences the development and maintenance of anxiety and obesity has been challenging to characterize, in part, due to methodological differences in chosen experimental and control diets. Within the same experiment, anxiety- and obesity-related effects were characterized in rats fed a Western diet (WD) relative to two control diets. Sixty Long-Evans rats split equally by sex were given standard diet (SD), control (i.e., high-carbohydrate) diet (HCD), or WD from weaning until sacrifice in early adulthood. Anxiety-related behavior was characterized in a modified open field test (mOFT) that allowed for the measurement of defensive behaviors (e.g., hiding within a refuge area), in addition to traditional OF measures (e.g., time in center). Both anxiety-related behaviors and hippocampal CA3 BDNF revealed specific sex differences. Neither adolescent weight gain of male and female rats, nor total body weight in early adulthood, were dependent on administration of HCD or WD, although the WD group consumed the most calories. In males only, administration of either WD or HCD resulted in elevated leptin levels relative to administration of the SD. Results indicate that SDs and HCDs are two distinct types of control diets that can affect comparability of studies and that using an SD might reveal more subtle metabolic changes. Control diet choice should be strongly considered during study design and interpretation, depending on specific research goals. Such studies should include both males and females as these effects are sex-specific.

The effects of antimicrobials and lipopolysaccharide on acute immune responsivity in pubertal male and female CD1 mice

Exposure to stress during critical periods of development—such as puberty—is associated with long-term disruptions in brain function and neuro-immune responsivity. However, the mechanisms underlying the effect of stress on the pubertal neuro-immune response has yet to be elucidated. Therefore, the objective of the current study was to investigate the effect antimicrobial and lipopolysaccharide (LPS) treatments on acute immune responsivity in pubertal male and female mice. Moreover, the potential for probiotic supplementation to mitigate these effects was also examined. 240 male and female CD1 mice were treated with one week of antimicrobial treatment (mixed antimicrobials or water) and probiotic treatment (L. rhamnosis R0011 and L. helveticus R0052 or L. helveticus R0052 and B. longum R0175) or placebo at five weeks of age. At six weeks of age (pubertal stress-sensitive period), the mice received a single injection of LPS or saline. Sickness behaviours were assessed, and mice were euthanized 8 h post-injection. Brain, blood, and intestinal samples were collected. The results indicated that the antimicrobial treatment reduced sickness behaviours, and potentiated LPS-induced plasma cytokine concentrations and pro-inflammatory markers in the pre-frontal cortex (PFC) and hippocampus, in a sex-dependent manner. However, probiotics reduced LPS-induced plasma cytokine concentrations along with hippocampal and PFC pro-inflammatory markers in a sex-dependent manner. L. rhamnosis R0011 and L. helveticus R0052 treatment also mitigated antimicrobial-induced plasma cytokine concentrations and sickness behaviours. These findings suggest that the microbiome is an important modulator of the pro-inflammatory immune response during puberty.

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Pubertal dysbiosis increases LPS-induced neuroinflammation.

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Pubertal dysbiosis increases LPS-induced plasma cytokine concentrations.

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Pubertal probiotic treatment reduces LPS-induced neuroinflammation.

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Pubertal probiotic treatment reduces LPS-induced plasma cytokine concentrations.

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Pubertal probiotic treatment reduces LPS-induced sickness.

The health effect of probiotics on high-fat diet-induced cognitive impairment, depression and anxiety: A cross-species systematic review

Obesity is a complex disease with many co-morbidities, including impaired cognitive functions. Obese individuals often contain an aberrant microbiota. Via the microbiota-gut-brain axis, the altered microbiota composition can affect cognition or induce anxiety- or depressive-like behavior. Probiotics have been shown to alleviate both obesity- and neurobehavioral disorder-related symptoms. Here, we evaluated previously published results on the effectiveness of probiotic intervention in alleviating obesity- or high-fat diet (HFD)-related cognitive impairment, depression and anxiety. A systematic search was performed in PubMed, Embase, and Google Scholar until June 2021 to identify relevant articles. Seventeen studies were included: one human and sixteen animal studies. Overall, the findings support the beneficial health effect of probiotics on HFD-induced cognitive impairment and anxiety. However, the results suggest that multi-strain probiotic treatments should be used with caution, especially in the absence of HFD-induced impairment. Future studies should overcome the large variation in study design and high risk of bias found in the current evidence. Nevertheless, probiotic treatment, in particular using the Lactobacillus genus, seems promising.

Probiotic effects on anxiety-like behavior in animal models

Gut microbiota have been shown to be useful in treating gastrointestinal diseases, cancer, obesity, infections, and, more recently, neuropsychiatric conditions such as degenerative diseases and depression. There has also been recent expansion in testing probiotics and prebiotics on anxiety-like behaviors in animals. Current results indicate that probiotic substances of the Lactobacillus and Bifidobacterium type are effective in reducing anxiety-like behaviors in mice or rats evaluated in the elevated plus-maze, the open-field, the light-dark box, and conditioned defensive burying. Probiotics are also effective in reducing serum or plasma corticosterone levels after acute stress. It is hypothesized that probiotics cause anxiolytic-like effects via vagal influences on caudal solitary nucleus, periaqueductal gray, central nucleus of the amygdala, and bed nucleus of the stria terminalis. Further experimentation is needed to trace the neurochemical anatomy underlying anxiolytic-like behaviors of gut microbiata exerting effects via vagal or nonvagal pathways.

Neurobiological effects of a probiotic-supplemented diet in chronically stressed male Long-Evans rats: Evidence of enhanced resilience

Probiotics that regulate the microbiome-gut-brain axis and provide mental health benefits to the host are referred to as psychobiotics. Preclinical studies have demonstrated psychobiotic effects on early life stress-induced anxiety- and depression-related behavior in rodents; however, the specific mechanisms remain ill-defined. In the current study, we investigated the effects of probiotic supplementation on neurobiological responses to chronic stress in adult male Long-Evans rats. Twenty-four rats were randomly assigned to probiotic (PB) or vehicle control (VEH) groups, then to either chronic unpredictable stress (CUS) or no-stress control (CON) conditions within each group (n = 6/subgroup). We hypothesized that PB supplementation would reduce markers of anxiety and enhance emotional resilience, especially in the CUS animals. In the cognitive uncertainty task, a nonsignificant trend was observed indicating that the PB-supplemented animals spent more time oriented toward the food reward than VEH animals. In the open-field task, CUS-PB animals spent more time in the center of the arena than CUS-VEH animals, an effect not observed between the two CON groups. In the swim task, the PB animals, regardless of stress assignment, exhibited increased floating, suggesting a conserved response in a challenging context. Focusing on the endocrine measures, higher dehydroepiandrosterone (DHEA)-to-corticosterone fecal metabolite ratios, a correlate of emotional resilience, were observed in PB animals. Further, PB animals exhibited reduced microglia immunoreactivity in the basolateral amygdala, possibly indicating a neuroprotective effect of PB supplements in this rodent model. These results provide evidence that PB supplementation interacts with stress exposure to influence adaptive responses associated with endocrine, neural, and behavioral indices of anxiety.

Effect of Bifidobacterium on olanzapine-induced body weight and appetite changes in patients with psychosis

RATIONALE

Gut microbiota plays an important role in host metabolism. Antipsychotic drugs can result in metabolic abnormalities. Probiotics may ameliorate the antipsychotic drug-induced metabolic abnormalities by regulating gut microbiota.

OBJECTIVE

To determine whether Bifidobacterium intervention can ameliorate olanzapine-induced weight increase.

METHODS

Enrolled patients were assigned to either the olanzapine or olanzapine plus Bifidobacterium group. The following were assessed: body weight, body mass index (BMI), appetite, latency to increased appetite, and baseline weight increase of more than 7%. All assessments were conducted at baseline and at 4, 8, and 12 weeks of treatment.

RESULTS

We enrolled 70 patients with schizophrenia or schizophrenic affective disorder, and 67 completed the study. Treatment for 4 weeks led to between-group differences in weight change (2.4 vs. 1.1 kg, p < 0.05) and BMI (0.9 vs. 0.4, p < 0.05). However, this difference disappeared at 8 and 12 weeks of treatment (both p > 0.05). The two groups did not differ in appetite increase at any time point (p > 0.05). The mean time from olanzapine initiation to appetite increase was also not significantly different between the two groups (t = 1.243, p = 0.220).

CONCLUSIONS

Probiotics may mitigate olanzapine-induced weight gain in the early stage of treatment and delay olanzapine-induced appetite increase.

Young at Gut-Turning Back the Clock with the Gut Microbiome

Over the past century, we have witnessed an increase in life-expectancy due to public health measures; however, we have also seen an increase in susceptibility to chronic disease and frailty. Microbiome dysfunction may be linked to many of the conditions that increase in prevalence with age, including type 2 diabetes, cardiovascular disease, Alzheimer's disease, and cancer, suggesting the need for further research on these connections. Moreover, because both non-modifiable (e.g., age, sex, genetics) and environmental (e.g., diet, infection) factors can influence the microbiome, there are vast opportunities for the use of interventions related to the microbiome to promote lifespan and healthspan in aging populations. To understand the mechanisms mediating many of the interventions discussed in this review, we also provide an overview of the gut microbiome's relationships with the immune system, aging, and the brain. Importantly, we explore how inflammageing (low-grade chronic inflammation that often develops with age), systemic inflammation, and senescent cells may arise from and relate to the gut microbiome. Furthermore, we explore in detail the complex gut-brain axis and the evidence surrounding how gut dysbiosis may be implicated in several age-associated neurodegenerative diseases. We also examine current research on potential interventions for healthspan and lifespan as they relate to the changes taking place in the microbiome during aging; and we begin to explore how the reduction in senescent cells and senescence-associated secretory phenotype (SASP) interplay with the microbiome during the aging process and highlight avenues for further research in this area.

Ingestion of probiotic (Lactobacillus helveticus and Bifidobacterium longum) alters intestinal microbial structure and behavioral expression following social defeat stress

Social stress exacerbates anxious and depressive behaviors in humans. Similarly, anxiety- and depressive-like behaviors are triggered by social stress in a variety of non-human animals. Here, we tested whether oral administration of the putative anxiolytic probiotic strains Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 reduces the striking increase in anxiety-like behavior and changes in gut microbiota observed following social defeat stress in Syrian hamsters. We administered the probiotic at two different doses for 21 days, and 16S rRNA gene amplicon sequencing revealed a shift in microbial structure following probiotic administration at both doses, independently of stress. Probiotic administration at either dose increased anti-inflammatory cytokines IL-4, IL-5, and IL-10 compared to placebo. Surprisingly, probiotic administration at the low dose, equivalent to the one used in humans, significantly increased social avoidance and decreased social interaction. This behavioral change was associated with a reduction in microbial richness in this group. Together, these results demonstrate that probiotic administration alters gut microbial composition and may promote an anti-inflammatory profile but that these changes may not promote reductions in behavioral responses to social stress.