Probiotics and their Effects on Metabolic Diseases: An Update

Microbiome-modulating nutraceuticals ameliorate dyslipidemia in type 2 diabetes: A systematic review, meta-analysis, and meta-regression of clinical trials

AIMS

Type 2 Diabetes is intrinsically linked to cardiovascular disease (CVD) via diabetic dyslipidemia, both of which remain global health concerns with annually increasing prevalence. Given the established links between gut microbiome dysbiosis and metabolic diseases, its modulation is an attractive target to ameliorate metabolic imbalances in such patients. There is a need to quantitively summarise, analyse, and describe future directions in this field.

METHODS

We conducted a systematic review, meta-analysis, and meta-regression following searches in major scientific databases for clinical trials investigating the effect of pro/pre/synbiotics on lipid profile published until April 2022. Data were pooled using random-effects meta-analysis and reported as mean differences with 95% confidence intervals (CIs). PROSPERO No. CRD42022348525.

RESULTS

Data from 47 trial comparisons across 42 studies (n = 2692) revealed that, compared to placebo/control groups, the administration of pro/pre/synbiotics was associated with statistically significant changes in total cholesterol (-9.97 mg/dL [95% CI: -15.08; -4.87], p < 0.0001), low-density lipoprotein (-6.29 mg/dL [95% CI: -9.25; -3.33], p < 0.0001), high-density lipoprotein (+3.21 mg/dL [95% CI: 2.20; 4.22], p < 0.0001), very-low-density lipoprotein (-4.52 mg/dL [95% CI: -6.36; -2.67], p < 0.0001) and triglyceride (-22.93 mg/dL [95% CI: -33.99; -11.87], p < 0.001). These results are influenced by patient characteristics such as age or baseline BMI, and intervention characteristics such as dosage and duration.

CONCLUSIONS

Our study shows that adjunct supplementation with a subset of pro/pre/synbiotics ameliorates dyslipidemia in diabetic individuals and has the potential to reduce CVD risk. However, widespread inter-study heterogeneity and the presence of several unknown confounders limit their adoption in clinical practice; future trials should be designed with these in mind.

An emerging strategy: probiotics enhance the effectiveness of tumor immunotherapy via mediating the gut microbiome

The occurrence and progression of tumors are often accompanied by disruptions in the gut microbiota. Inversely, the impact of the gut microbiota on the initiation and progression of cancer is becoming increasingly evident, influencing the tumor microenvironment (TME) for both local and distant tumors. Moreover, it is even suggested to play a significant role in the process of tumor immunotherapy, contributing to high specificity in therapeutic outcomes and long-term effectiveness across various cancer types. Probiotics, with their generally positive influence on the gut microbiota, may serve as effective agents in synergizing cancer immunotherapy. They play a crucial role in activating the immune system to inhibit tumor growth. In summary, this comprehensive review aims to provide valuable insights into the dynamic interactions between probiotics, gut microbiota, and cancer. Furthermore, we highlight recent advances and mechanisms in using probiotics to improve the effectiveness of cancer immunotherapy. By understanding these complex relationships, we may unlock innovative approaches for cancer diagnosis and treatment while optimizing the effects of immunotherapy.

Probiotic potential of Bacillus Isolates from Polish Bee Pollen and Bee Bread

The main goal of this study was the evaluation of the probiotic potential of 10 Bacillus spp. strains isolated from 5 bee bread and 3 bee pollen samples. The antagonistic interaction with Staphylococcus aureus and Escherichia coli was a primary criterion for the preliminary selection of the isolates. Three out of ten strains-PY2.3 (isolated from pollen), BP20.15 and BB10.1 (both isolated from bee bread)-were found to be possible probiotic strains. All these strains are safe for humans (exhibiting [Formula: see text]-hemolytic activity) and meet all essential requirements for probiotics in terms of viability in the presence of bile salts and acid conditions, hydrophobicity, auto-aggregation, and co-aggregation with the cells of important human pathogenic bacteria. They also assimilate more than 30% of cholesterol after 24 h of incubation. These three isolates are resistant to penicillin but sensitive (or exhibit moderate resistance) to the other nine antibiotics tested herein. On the basis of whole-genome sequencing, BP20.15 and BB10.1 were classified as B. subtilis and PY2.3 as B. velezensis. Moreover, genomic analyses revealed that all these isolates are potential producers of different antimicrobial compounds, including bacteriocins and secondary metabolites. The outcomes of this study have proven that some of the Bacillus strains isolated from bee pollen or bee bread are potential probiotics.

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.

Effects of probiotic supplementation on major cardiovascular-related parameters in patients with type-2 diabetes mellitus: a secondary-data analysis of a randomized double-blind controlled trial

BACKGROUND

Patients with type-2 diabetes mellitus (T2DM), have a higher risk of future cardiovascular diseases (CVD). Meanwhile, probiotics are shown to positively impact CVD-related parameters. This randomized controlled trial sought to evaluate the effects of probiotic supplementation on fundamental CVD-related parameters including atherogenic index of plasma (AIPs), blood pressure, the Framingham risk score, and antioxidant markers in patients with T2DM.

METHODS

Eligible participants were randomly assigned to receive 2 capsules/day of probiotics [each containing 500 mg of L.acidophilus(5 × 10¹⁰ CFU/g), L.plantarum(1.5 × 10¹⁰ CFU/g), L.fermentum(7 × 10⁹ CFU/g), L.Gasseri(2 × 10¹⁰ CFU/g) and 38.5 mg of fructo-oligo-saccharides], or placebo for 6 weeks. Systolic and diastolic blood pressures (SBP and DBP, respectively), mean arterial blood pressure (MAP), atherogenic indices (the ratios of TC/HDL-C, LDL-C/HDL-C, and logTG/HDL-C), the 10-year Framingham CVD risk score, as well as total anti-oxidant capacity (TAC), paraoxonase (PON) and total oxidant status (TOS) were evaluated before and after the study. Final analyses were adjusted based on baseline parameters, and potential covariates including age, sex, PUFA and sodium intakes.

RESULTS

Sixty participants completed the study. Compared with placebo, probiotic supplementation resulted in a significant decrease in SBP[-9.24 mmHg(- 14.5, - 3.9)], DBP[- 3.71 mmHg(- 6.59, - 0.83)], MAP[- 5.55 mmHg(- 8.8, - 2.31)], the Framingham risk categories [medium-low(1.5) vs. 2 (medium)] and logTG/HDL-C ratio [- 0.08 (- 0.14, 0)] (All P < 0.05) at the end of the study. No significant changes were observed in the antioxidant markers.

CONCLUSION

Overall, probiotic supplementation for 6 weeks led to a significant improvement in major CVD-related parameters in populations with T2DM, suggesting the possible beneficial role of probiotics in lowering the risk of future CVDs associated with diabetes. Nevertheless, more studies are needed to confirm the veracity of these results.

TRIAL REGISTRATION

IRCT2013100714925N1 (registered on November, 9th, 2013).

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Nanomaterial-based encapsulation for controlled gastrointestinal delivery of viable probiotic bacteria

Probiotics are microorganisms that have beneficial health effects when administered in adequate dosages. The oral administration of probiotic bacteria is widely considered beneficial for both intestinal as well as systemic health but its clinical efficacy is conflicted in the literature. This may at least in part be due to the loss of viability during gastrointestinal passage resulting in poor intestinal delivery. Microencapsulation technology has been proposed as a successful strategy to address this problem by maintaining the viability of probiotics, thereby improving their efficacy following oral administration. More recently, nanomaterials have demonstrated significant promise as encapsulation materials to improve probiotic encapsulation. The integration of nanotechnology with microencapsulation techniques can improve the controlled delivery of viable probiotic bacteria to the gut. The current review aims at summarizing the types of nanomaterials used for the microencapsulation of probiotics and showing how they can achieve the delivery and controlled release of probiotics at the site of action.

Probiotics have beneficial metabolic effects in patients with type 2 diabetes mellitus: a meta-analysis of randomized clinical trials

Probiotics have been reported to have a positive impact on the metabolic control of patients with type 2 diabetes. We aimed to systematically evaluate the effects of probiotics on cardiometabolic parameters in type 2 diabetes based on randomized controlled studies. MEDLINE, Embase, and CENTRAL databases were reviewed to search for randomized controlled trials that examined the effects of probiotic supplementation on cardiometabolic parameters in patients with type 2 diabetes. 32 trials provided results suitable to be included in the analysis. The effects of probiotics were calculated for the following parameters: BMI, total cholesterol levels, LDL, triglycerides, HDL, CRP, HbA1c levels, fasting plasma glucose, fasting insulin levels, systolic and diastolic blood pressure values. Data analysis showed a significant effect of probiotics on reducing total cholesterol, triglyceride levels, CRP, HbA1c, fasting plasma glucose, fasting insulin levels, and both systolic and diastolic blood pressure values. Supplementation with probiotics increased HDL levels however did not have a significant effect on BMI or LDL levels. Our data clearly suggest that probiotics could be a supplementary therapeutic approach in type 2 diabetes mellitus patients to improve dyslipidemia and to promote better metabolic control. According to our analysis, probiotic supplementation is beneficial in type 2 diabetes mellitus.

Lactobacillus sakei S1 Improves Colitis Induced by 2,4,6-Trinitrobenzene Sulfonic Acid by the Inhibition of NF-κB Signaling in Mice

Lactobacillus sakei S1 strongly inhibits the expression of interleukin (IL)-6 and IL-1β in lipopolysaccharide-induced peritoneal macrophages by a mechanism for which lactic acid bacteria from kimchi that inhibit tumor necrosis factor-alpha (TNF-κ) were isolated. Therefore, we further evaluated the protective effect of this strain on the colitis mouse model induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). TNBS significantly elevated myeloperoxidase (MPO) expression, macroscopic scores, and colon shortening. Oral L. sakei S1 administration resulted in reduction of TNBS-induced loss in body weight, colon shortening, MPO activity, expression of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-κB). L. sakei S1 inhibited the expression of inflammatory cytokines IL-1β, IL-6 and TNF-κ, induced by TNBS, but enhanced IL-10 expression. L. sakei S1 showed resistance to artificial digestive juices and adherence to intestinal epithelial Caco-2 cells. Thus, L. sakei S1 may inhibit the NF-κB pathway and be used in functional food to treat colitis.

Deciphering the microbiome shift during fermentation of medicinal plants

The importance of the human-microbiome relationship for positive health outcomes has become more apparent over the last decade. Influencing the gut microbiome via modification of diet represents a possibility of maintaining a healthy gut flora. Fermented food and lactic acid bacteria (LAB) display a preventive way to inhibit microbial dysbioses and diseases, but their ecology on plants is poorly understood. We characterized the microbiome of medicinal plants (Matricaria chamomilla L. and Calendula officinalis L.) using 16S rRNA gene profiling from leaves that were fermented over a six-week time course. The unfermented samples were characterized by a distinct phyllosphere microbiome, while the endosphere revealed a high similarity. During fermentation, significant microbial shifts were observed, whereby LAB were enhanced in all approaches but never numerically dominated. Among the LAB, Enterococcaceae were identified as the most dominant family in both plants. M. chamomilla community had higher relative abundances of Lactobacillaceae and Carnobacteriaceae, while C. officinalis showed a higher presence of Leuconostocaceae and Streptococcaceae. The natural leaf microbiome and the indigenous LAB communities of field-grown Asteraceae medicinal plants are plant-specific and habitat-specific and are subjected to significant shifts during fermentation. Leaf surfaces as well as leaf endospheres were identified as sources for biopreservative LAB.

Probiotics in Extraintestinal Diseases: Current Trends and New Directions

Probiotics are defined as live microorganisms that when administered in adequate amounts confer a health benefit to the host. Their positive supplementation outcomes on several gastrointestinal disorders are well defined. Nevertheless, their actions are not limited to the gut, but may also impart their beneficial effects at distant sites and organs. In this regard, in this review article we: (i) comprehensively describe the main mechanisms of action of probiotics at distant sites, including bones, skin, and brain; (ii) critically present their therapeutic potential against bone, skin, and neuronal diseases (e.g., osteoporosis, non-healing wounds and autoimmune skin illnesses, mood, behavior, memory, and cognitive impairments); (iii) address the current gaps in the preclinical and clinical research; and (iv) indicate new research directions and suggest future investigations.

Probiotic strains of lactobacilli and bifidobacteria alter pro- and anti-inflammatory cytokines production in rats with monosodium glutamate-induced obesity

The aim of this study was to investigate the effect of probiotic strains of Lactobacillus casei IMV B-7280, Bifidobacterium animalis VKL, B. animalis VKB on the pro- and anti-inflammatory cytokines production in Wistar male rats with monosodium glutamate (MSG)-induced obesity. It was established that neonatal administration of MSG to rats leads to increasing levels of the interleukin (IL)-1β and IL-12, and to decreasing ofthe IL-4, IL-10 and tumor growthfactor (TGF)-β levels in the bloodserum. After administration of the B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition to obese rats the level of the IL-lP in blood serum wasn't differ from that in the obese rats, that didn't receive of the probiotic bacteria. But there was no statistically signifcant difference comparing with intact rats. The level of the IL-12B p4O in blood serum was decreased under influence of the B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition (18.9%, p < 0.05) and B. animalis VKL (10.5%, p < 0.05) compared with obese rats, not receiving probiotic bacteria, but remained higher than in intact animals. After administration to obese rats ofthe B. animalis VKL - B. animalis VKB - L. casei IMV B-7280 composition the levels ofthe IL-4, IL- 10 and TGF-β increased in blood serum comparing with obese rats, not receiving probiotic bacteria. The level of the IL-10 also increased under influence of the B. animalis VKB, and IL-4 - under influence of the L. casei IMVB-7280. Our results suggest that these probiotic bacteria and probiotic composition are able to down-regulation the inflammation in rats with MSG-induced obesity but the strongest anti-inflammatory effects have probiotic composition. The ability of lactobacilli and bifdobacteria to alter the pro- and anti-inflammatory cytokines production, opens perspectives to create new treatments for obesity and metabolic syndrome based on probiotics.

Specific synbiotics in early life protect against diet-induced obesity in adult mice

AIMS

The metabolic state of human adults is associated with their gut microbiome. The symbiosis between host and microbiome is initiated at birth, and early life microbiome perturbation can disturb health throughout life. Here, we determined how beneficial microbiome interventions in early life affect metabolic health in adulthood.

METHODS

Postnatal diets were supplemented with either prebiotics (scGOS/lcFOS) or synbiotics (scGOS/lcFOS with Bifidobacterium breve M-16 V) until post-natal (PN) day 42 in a well-established rodent model for nutritional programming. Mice were subsequently challenged with a high-fat Western-style diet (WSD) for 8 weeks. Body weight and composition were monitored, as was gut microbiota composition at PN21, 42 and 98. Markers of glucose homeostasis, lipid metabolism and host transcriptomics of 6 target tissues were determined in adulthood (PN98).

RESULTS

Early life synbiotics protected mice against WSD-induced excessive fat accumulation throughout life, replicable in 2 independent European animal facilities. Adult insulin sensitivity and dyslipidaemia were improved and most pronounced changes in gene expression were observed in the ileum. We observed subtle changes in faecal microbiota composition, both in early life and in adulthood, including increased abundance of Bifidobacterium. Microbiota transplantation using samples collected from synbiotics-supplemented adolescent mice at PN42 to age-matched germ-free recipients did not transfer the beneficial phenotype, indicating that synbiotics-modified microbiota at PN42 is not sufficient to transfer long-lasting protection of metabolic health status.

CONCLUSION

Together, these findings show the potential and importance of timing of synbiotic interventions in early life during crucial microbiota development as a preventive measure to lower the risk of obesity and improve metabolic health throughout life.

Effect of Lactobacillus on body weight and body fat in overweight subjects: a systematic review of randomized controlled clinical trials

Gut microbiota is important for maintaining body weight. Modulation of gut microbiota by probiotics may result in weight loss and thus help in obesity treatment. The aim of this systematic review was to evaluate the effects of Lactobacillus on weight loss and/or fat mass in overweight adults. A search was performed on the Medline (PubMed) and Scopus electronic databases using the search terms: 'probiotics', 'Lactobacillus, 'obesity', 'body weight changes', 'weight loss', 'overweight', 'abdominal obesity', 'body composition', 'body weight', 'body fat' and 'fat mass'. In the total were found 1567 articles, but only 14 were included in this systematic review. Of these nine showed decreased body weight and/or body fat, three did not find effect and two showed weight gain. Results suggest that the beneficial effects are strain dependent. It can highlight that Lactobacillus plantarum and Lactobacillus rhamnosus when combined with a hypocaloric diet, L. plantarum with Lactobacillus curvatus, Lactobacillus gasseri, Lactobacillus amylovorus, Lactobacillus acidophilus and Lactobacillus casei with phenolic compounds, and multiple species of Lactobacillus.

Probiotics and Disease: A Comprehensive Summary-Part 3, Cardiometabolic Disease and Fatigue Syndromes

This article series provides a literature review of the disease-specific probiotic strains, associated with cardiometabolic diseases and fatigue syndromes, studied in published clinical trials in humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article (part 1) focused on mental health and neurological conditions and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. This third article (part 3) explores the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes. Future articles will review conditions related to respiratory, ear, nose, and throat infections and infectious diseases; autoimmunity and dermatological conditions; cancer; and gastrointestinal and genitourinary, followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Construction of a Recombinant Leuconostoc mesenteroides CJNU 0147 Producing 1,4-Dihydroxy-2-Naphthoic Acid, a Bifidogenic Growth Factor

1,4-Dihydroxy-2-naphthoic acid (DHNA), a precursor of menaquinone (vitamin K2), has an effect on growth stimulation of bifidobacteria and prevention of osteoporosis, making it a promising functional food material. Therefore, we tried to clone the menB gene encoding DHNA synthase from Leuconostoc mesenteroides CJNU 0147. Based on the genome sequence of Leu. mesenteroides ATCC 8293 (GenBank accession no., CP000414), a primer set (Leu_menBfull_F and Leu_menBfull_R) was designed for the PCR amplification of menB gene of CJNU 0147. A DNA fragment (1,190 bp), including the menB gene, was amplified, cloned into pGEM-T Easy vector, and sequenced. The deduced amino acid sequence of MenB (DHNA synthase) protein of CJNU 0147 had a 98% similarity to the corresponding protein of ATCC 8293. The menB gene was subcloned into pCW4, a lactic acid bacteria - E. coli shuttle vector, and transferred to CJNU 0147. The transcription of menB gene of CJNU 0147 (pCW4::menB) was increased, when compared with those of CJNU 0147 (pCW4) and CJNU 0147 (−). The DHNA was produced from it at a detectable level, indicating that the cloned menB gene of CJNU 0147 encoded a DHNA synthase which is responsible for the production of DHNA, resulting in an increase of bifidogenic growth stimulation activity.

Effect of Cucurbita ficifolia and Probiotic Yogurt Consumption on Blood Glucose, Lipid Profile, and Inflammatory Marker in Type 2 Diabetes

Background:

Control of blood sugar, hypertension, and dyslipidemia are key factors in diabetes management. Cucurbita ficifolia (pumpkin) is a vegetable which has been used traditionally as a remedy for diabetes in Iran. In addition, consumption of probiotics may have beneficial effects on people with Type 2 diabetes. The aim of this study was an investigation of the effects of C. ficifolia and probiotic yogurt consumption alone or at the same time on blood glucose and serum lipids in diabetic patients.

Methods:

Eighty eligible participants randomly were assigned to four groups: 1 - green C. ficifolia (100 g); 2 - probiotic yogurt (150 g); 3 - C. ficifolia plus probiotic yogurt (100 g C. ficifolia plus 150 g yogurt); and 4 -control (dietary advice) for 8 weeks. Blood pressure, glycemic response, lipid profile, and high-sensitive C-reactive protein (hsCRP) were measured before and after the intervention.

Results:

Total cholesterol (TC) decreased significantly in yogurt and yogurt plus C. ficifolia groups (within groups P = 0.010, and P < 0.001, respectively). C. ficifolia plus yogurt consumption resulted in a decrease in triglyceride (TG) and an increase in high-density lipoprotein cholesterol (HDL-C) (within groups P < 0.001 and P = 0.001, respectively). All interventions led to a significant decrease in blood sugar, hemoglobin A1c (HbA1c), hsCRP, and low-density lipoprotein cholesterol (LDL-C) level within groups. Blood pressure decreased significantly in Cucurbita group and yogurt group (within groups P < 0.001, and P = 0.001 for systolic blood pressure [SBP] and P < 0.001, and P = 0.004 for diastolic blood pressure [DBP], respectively). All variables changed between groups significantly except LDL-C level.

Conclusions:

Variables including TG, HDL-C, TC, fasting blood sugar, HbA1c, SBP, DBP, and hsCRP changed beneficially between groups. It seems that consumption of C. ficifolia and probiotic yogurt may help treatment of diabetic patients.

Impact of kefir derived Lactobacillus kefiri on the mucosal immune response and gut microbiota

The evaluation of the impact of probiotics on host health could help to understand how they can be used in the prevention of diseases. On the basis of our previous studies and in vitro assays on PBMC and Caco-2 ccl20:luc reporter system presented in this work, the strain Lactobacillus kefiri CIDCA 8348 was selected and administrated to healthy Swiss mice daily for 21 days. The probiotic treatment increased IgA in feces and reduced expression of proinflammatory mediators in Peyer Patches and mesenteric lymph nodes, where it also increased IL-10. In ileum IL-10, CXCL-1 and mucin 6 genes were upregulated; meanwhile in colon mucin 4 was induced whereas IFN-γ, GM-CSF, and IL-1β genes were downregulated. Moreover, ileum and colon explants showed the anti-inflammatory effect of L. kefiri since the LPS-induced increment of IL-6 and GM-CSF levels in control mice was significantly attenuated in L. kefiri treated mice. Regarding fecal microbiota, DGGE profiles allowed differentiation of experimental groups in two separated clusters. Quantitative PCR analysis of different bacterial groups revealed only significant changes in Lactobacillus population. In conclusion, L. kefiri is a good candidate to be used in gut inflammatory disorders.

The effects of probiotic supplementation on markers of blood lipids, and blood pressure in patients with prediabetes: a randomized clinical trial

BACKGROUND

Prediabetes is a high-risk condition for type 2 diabetes mellitus. The growing prevalence of diabetes emphasizes on the necessity of concentrating on various strategies to prediabetes prevention and management. Probiotics as a group of functional foods might exert antidiabetic effects. This study aimed to assess the effects of probiotic administration on blood lipid profile and blood pressure in patients with prediabetes.

METHODS

This randomized controlled trial consisted of 60 prediabetic patients, aged 25-65 years old, that were randomly assigned to the intervention (receiving 500 mg probiotic capsules, n = 30) or control group (receiving placebo, n = 30) for 8-week period. Demographic and anthropometric data were collected at baseline. Blood samples were collected at baseline and after 8 weeks for biochemical measurements. Blood pressure was measured at the baseline an after 8 weeks of intervention. Data regarding dietary intakes and physical activity were also collected during the study. We used SPSS software version 16 (SPSS Inc. Chicago, USA) for data analyzing.

RESULTS

Probiotic supplementation did not contribute to significant changes in total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, Triglycerides (TG), TG/LDL and LDL/HDL ratios, after 8 weeks. After adjusting for potential confounders, HDL-cholesterol reduced significantly in the placebo group compared with probiotic group. Percent change in systolic blood pressure was significantly different in the probiotic group in comparison with a placebo group (-3.10 ± 2.22 vs. 3.24 ± 1.96, P = 0.01), although this significance did not exist anymore after adjusting for confounders (P > 0.05).

CONCLUSIONS

Our study showed that probiotics did not have significant effects on lipid markers although they had positive effects on systolic blood pressure.

Physiology and its importance for reference intervals

Reference intervals are ideally defined on apparently healthy individuals and should be distinguished from clinical decision limits that are derived from known diseased patients. Knowledge of physiological changes is a prerequisite for understanding and developing reference intervals. Reference intervals may differ for various subpopulations because of differences in their physiology, most obviously between men and women, but also in childhood, pregnancy and the elderly. Changes in laboratory measurements may be due to various physiological factors starting at birth including weaning, the active toddler, immunological learning, puberty, pregnancy, menopause and ageing. The need to partition reference intervals is required when there are significant physiological changes that need to be recognised. It is important that laboratorians are aware of these changes otherwise reference intervals that attempt to cover a widened inter-individual variability may lose their usefulness. It is virtually impossible for any laboratory to directly develop reference intervals for each of the physiological changes that are currently known, however indirect techniques can be used to develop or validate reference intervals in some difficult situations such as those for children. Physiology describes our life's journey, and it is only when we are familiar with that journey that we can appreciate a pathological departure.