Immune-related microRNAs in breast milk and their relation to regulatory T cells in breastfed children.

BACKGROUND: The immunomodulatory capacity of breast milk may partially be mediated by microRNAs (miRNA), small RNA molecules that regulate gene expression on a post-transcriptional level and are hypothesized to be involved in modulation of immunological pathways. Here, we evaluate the expression of immune-related miRNAs in breast milk after pre- and postnatal supplementation with Limosilactobacillus reuteri and omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), and the association to infant regulatory T cell (Treg) frequencies. METHODS: One-hundred and twenty women included in a double-blind, randomized, placebo-controlled allergy intervention trial received L. reuteri and/or ω-3 PUFAs daily from gestational week 20. Using Taqman qPCR, 24 miRNAs were analyzed from breast milk obtained at birth (colostrum) and after 3 months (mature milk) of lactation. The proportion of activated and resting Treg cells were analyzed in infant blood using flow cytometry at 6, 12, and 24 months. RESULTS: Relative expression changed significantly over the lactation period for most of the miRNAs; however, the expression was not significantly influenced by any of the supplements. Colostrum miR-181a-3p correlated with resting Treg cell frequencies at 6 months. Colostrum miR-148a-3p and let-7d-3p correlated with the frequencies of activated Treg cells at 24 months, as did mature milk miR-181a-3p and miR-181c-3p. CONCLUSION: Maternal supplementation with L. reuteri and ω-3 PUFAs did not significantly affect the relative miRNA expression in breast milk. Interestingly, some of the miRNAs correlate with Treg subpopulations in the breastfed children, supporting the hypothesis that breast milk miRNAs could be important in infant immune regulation. TRIAL REGISTRATION: ClinicalTrials.gov-ID: NCT01542970.

Potential Modulation of Inflammation and Physical Function by Combined Probiotics, Omega-3 Supplementation and Vitamin D Supplementation in Overweight/Obese Patients with Chronic Low-Grade Inflammation: A Randomized, Placebo-Controlled Trial.

Obesity is characterized by low-grade inflammation and increased gut permeability. Here, we aim to evaluate the effect of a nutritional supplement on these parameters in subjects with overweight and obesity. A double-blinded, randomized clinical trial was conducted in 76 adults with overweight or obesity (BMI 28 to 40) and low-grade inflammation (high-sensitivity C-reactive protein (hs-CRP) between 2 and 10 mg/L). The intervention consisted of a daily intake of a multi-strain probiotic of Lactobacillus and Bifidobacterium, 640 mg of omega-3 fatty acids (n-3 FAs), and 200 IU of vitamin D (n = 37) or placebo (n = 39), administered for 8 weeks. hs-CRP levels did not change post-intervention, other than an unexpected slight increase observed in the treatment group. Interleukin (IL)-6 levels decreased in the treatment group (p = 0.018). The plasma fatty acid (FA) levels of the arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio and n-6/n-3 ratio (p < 0.001) decreased, and physical function and mobility improved in the treatment group (p = 0.006). The results suggest that hs-CRP may not be the most useful inflammatory marker, but probiotics, n-3 FAs, and vitamin D, as non-pharmaceutical supplements, may exert modest effects on inflammation, plasma FA levels, and physical function in patients with overweight and obesity and associated low-grade inflammation.

Evaluation of five column-based isolation kits and their ability to extract miRNA from human milk.

MicroRNA can be found in various body fluids, including breast milk. MicroRNA may be transferred from mother to infant via breast milk and potentially regulate the development of the infant's immune system on a post-transcriptional level. This study aimed to determine the microRNA extraction efficiency of five RNA extraction kits from human skim milk samples. Their efficiency was determined by comparing microRNA concentrations, total RNA yield and purity. Furthermore, hsa-miR-148a-3p expression and the recovery of an exogenous control, cel-miR-39-3p, were quantified using qPCR. Each kit extracted different amounts of microRNA and total RNA, with one kit tending to isolate the highest amount of both RNA species. Based on these results, the extraction kit ReliaPrep™ miRNA Cell and Tissue Miniprep System from Promega was found to be the most appropriate kit for microRNA extraction from human skim milk. Moreover, further research is needed to establish a standardized protocol for microRNA extraction from breast milk.

Breast milk microRNAs: Potential players in oral tolerance development.

Breast milk is an essential source of nutrition and hydration for the infant. In addition, this highly complex biological fluid contains numerous immunologically active factors such as microorganisms, immunoglobulins, cytokines and microRNAs (miRNAs). Here, we set out to predict the function of the top 10 expressed miRNAs in human breast milk, focusing on their relevance in oral tolerance development and allergy prevention in the infant. The top expressed miRNAs in human breast milk were identified on basis of previous peer-reviewed studies gathered from a recent systematic review and an updated literature search. The miRNAs with the highest expression levels in each study were used to identify the 10 most common miRNAs or miRNA families across studies and these were selected for subsequent target prediction. The predictions were performed using TargetScan in combination with the Database for Annotation, Visualization and Integrated Discovery. The ten top expressed miRNAs were: let-7-5p family, miR-148a-3p, miR-30-5p family, miR-200a-3p + miR-141-3p, miR-22-3p, miR-181-5p family, miR-146b-5p, miR-378a-3p, miR-29-3p family, miR-200b/c-3p and miR-429-3p. The target prediction identified 3,588 potential target genes and 127 Kyoto Encyclopedia of Genes and Genomes pathways; several connected to the immune system, including TGF-b and T cell receptor signaling and T-helper cell differentiation. This review highlights the role of breast milk miRNAs and their potential contribution to infant immune maturation. Indeed, breast milk miRNAs seem to be involved in several pathways that influence oral tolerance development.

Potential Modulation of Inflammation by Probiotic and Omega-3 Supplementation in Elderly with Chronic Low-Grade Inflammation-A Randomized, Placebo-Controlled Trial.

Probiotic and omega-3 supplements have been shown to reduce inflammation, and dual supplementation may have synergistic health effects. We investigated if the novel combination of a multi-strain probiotic (containing B. lactis Bi-07, L. paracasei Lpc-37, L. acidophilus NCFM, and B. lactis Bl-04) alongside omega-3 supplements reduces low-grade inflammation as measured by high-sensitivity C-reactive protein (hs-CRP) in elderly participants in a proof-of-concept, randomized, placebo-controlled, parallel study (NCT04126330). In this case, 76 community-dwelling elderly participants (median: 71.0 years; IQR: 68.0-73.8) underwent an intervention with the dual supplement (n = 37) or placebo (n = 39) for eight weeks. In addition to hs-CRP, cytokine levels and intestinal permeability were also assessed at baseline and after the eight-week intervention. No significant difference was seen for hs-CRP between the dual supplement group and placebo. However, interestingly, supplementation did result in significant increases in the level of the anti-inflammatory marker IL-10. In addition, dual supplementation increased levels of valeric acid, further suggesting the potential of the supplements in reducing inflammation and conferring health benefits. Together, the results suggest that probiotic and omega-3 dual supplementation exerts modest effects on inflammation and may have potential use as a non-pharmacological treatment for low-grade inflammation in the elderly.

Mental health as a prerequisite for functioning as optimally as possible in old age: A phenomenological approach.

AIM: To describe the impact of mental health on the ability to function optimally among older adults experiencing mental health issues. DESIGN: This study had a descriptive qualitative design. METHODS: Six older females with a Hospital Anxiety and Depression Scale (HADS) score of ≥8 on either of the subscales (depression or anxiety) participated in individual interviews. All data were analysed using a phenomenological approach influenced by Giorgi. RESULTS: The phenomenological analysis led to a structured synthesis comprising the following three themes: (a) life situations affecting mental health, (b) consequences of mental health in everyday life and (c) strategies for maintaining mental health.

The Effect of Probiotics on Health Outcomes in the Elderly: A Systematic Review of Randomized, Placebo-Controlled Studies.

Increasing evidence suggests that probiotic supplementation may be efficacious in counteracting age-related shifts in gut microbiota composition and diversity, thereby impacting health outcomes and promoting healthy aging. However, randomized controlled trials (RCTs) with probiotics in healthy older adults have utilized a wide variety of strains and focused on several different outcomes with conflicting results. Therefore, a systematic review was conducted to determine which outcomes have been investigated in randomized controlled trials with probiotic supplementation in healthy older adults and what has been the effect of these interventions. For inclusion, studies reporting on randomized controlled trials with probiotic and synbiotic supplements in healthy older adults (defined as minimum age of 60 years) were considered. Studies reporting clinical trials in specific patient groups or unhealthy participants were excluded. In addition to assessment of eligibility and data extraction, each study was examined for risk of bias and quality assessment was performed by two independent reviewers. Due to the heterogeneity of outcomes, strains, study design, duration, and methodology, we did not perform any meta-analyses and instead provided a narrative overview of the outcomes examined. Of 1997 potentially eligible publications, 17 studies were included in this review. The risk of bias was low, although several studies failed to adequately describe random sequence generation, allocation concealment, and blinding. The overall study quality was high; however, many studies did not include sample calculations, and the majority of studies had a small sample size. The main outcomes examined in the trials included microbiota composition, immune-related measurements, digestive health, general well-being, cognitive function, and lipid and other biomarkers. The most commonly assessed outcome with the most consistent effect was microbiota composition; all but one study with this outcome showed significant effects on gut microbiota composition in healthy older adults. Overall, probiotic supplementation had modest effects on markers of humoral immunity, immune cell population levels and activity, as well as the incidence and duration of the common cold and other infections with some conflicting results. Digestive health, general-well-being, cognitive function, and lipid and other biomarkers were investigated in a very small number of studies; therefore, the impact on these outcomes remains inconclusive. Probiotics appear to be efficacious in modifying gut microbiota composition in healthy older adults and have moderate effects on immune function. However, the effect of probiotic supplementation on other health outcomes remains inconclusive, highlighting the need for more well-designed, sufficiently-powered studies to investigate if and the mechanisms by which probiotics impact healthy aging.

Non-Coding RNAs in Human Breast Milk: A Systematic Review.

Breast milk is the primary source of nutrition and hydration for the newborn infant but also plays an important role in the child's first immune defense. Additionally, several breast milk factors have been implicated in immune-related health outcomes later in life, including immunoglobulins, cytokines, chemokines, growth factors and, more recently, non-coding RNA (ncRNA) species. In this systematic review, we provide a comprehensive summary of the current literature on endogenous ncRNAs found in human breast milk. Thirty (30) relevant studies were identified and, whilst the majority studies focused on microRNAs (miRNAs), there is evidence that breast milk contains high quantities of RNA which also include long-coding RNAs, circular RNAs, as well as other short RNAs and fragmented tRNA and rRNAs. Among studies investigating miRNAs, miR-148a-3p, miR-30a/d-5p, miR-22-3p, miR-146b-5p, miR-200a/c-3p, and the 5p end of the let-7 miRNAs were commonly reported among the top 10 miRNAs in the cell, lipid, and skim milk fractions of breast milk. Methodological difference and small sample sizes limit the possibility of conclusively identifying which maternal and infant characteristics affect the miRNA profile. The highly expressed miRNAs were generally reported to be similar across lactational stage, milk fraction, maternal and infant characteristics, or infant growth and health. All the same, individual studies identify potential differences in miRNA expression levels which should be confirmed by future studies. Stability, uptake, and physiological functions of miRNAs were also considered in several studies. Breast milk miRNAs are relatively resistant to a range of harsh conditions and uptake experiments suggest that extracellular vesicles containing miRNAs and circular RNAs can be taken up by intestinal epithelial cells. Although the evidence regarding the functional effect of breast milk miRNAs is limited, the predicted functions range from metabolic and biosynthetic processes to signaling pathways, cellular adhesion, communication, growth, and differentiation. Finally, this systematic review highlights some of the methodological challenges and knowledge gaps which can help direct future research in this field. In particular, it is important to further investigate the bioavailability of miRNAs in different milk fractions, and to characterize other ncRNAs which are largely unstudied. Systematic Review Registration: PROSPERO https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=138989, identifier CRD42020138989.

The Potential Effects of Probiotics and ω-3 Fatty Acids on Chronic Low-Grade Inflammation.

Chronic low-grade inflammation negatively impacts health and is associated with aging and obesity, among other health outcomes. A large number of immune mediators are present in the digestive tract and interact with gut bacteria to impact immune function. The gut microbiota itself is also an important initiator of inflammation, for example by releasing compounds such as lipopolysaccharides (LPS) that may influence cytokine production and immune cell function. Certain nutrients (e.g., probiotics, ω-3 fatty acids [FA]) may increase gut microbiota diversity and reduce inflammation. Lactobacilli and Bifidobacteria, among others, prevent gut hyperpermeability and lower LPS-dependent chronic low-grade inflammation. Furthermore, ω-3 FA generate positive effects on inflammation-related conditions (e.g., hypertriglyceridemia, diabetes) by interacting with immune, metabolic, and inflammatory pathways. Ω-3 FA also increase LPS-suppressing bacteria (i.e., Bifidobacteria) and decrease LPS-producing bacteria (i.e., Enterobacteria). Additionally, ω-3 FA appear to promote short-chain FA production. Therefore, combining probiotics with ω-3 FA presents a promising strategy to promote beneficial immune regulation via the gut microbiota, with potential beneficial effects on conditions of inflammatory origin, as commonly experienced by aged and obese individuals, as well as improvements in gut-brain-axis communication.

Differences in Gut Microbiome Composition between Senior Orienteering Athletes and Community-Dwelling Older Adults.

BACKGROUND: Gastrointestinal (GI) health is an important aspect of general health. Gastrointestinal symptoms are of specific importance for the elderly, an increasing group globally. Hence, promoting the elderly's health and especially gastrointestinal health is important. Gut microbiota can influence gastrointestinal health by modulation of the immune system and the gut-brain axis. Diverse gut microbiota have been shown to be beneficial; however, for the elderly, the gut microbiota is often less diverse. Nutrition and physical activity, in particular, are two components that have been suggested to influence composition or diversity. MATERIALS AND METHODS: In this study, we compared gut microbiota between two groups of elderly individuals: community-dwelling older adults and physically active senior orienteering athletes, where the latter group has less gastrointestinal symptoms and a reported better well-being. With this approach, we explored if certain gut microbiota were related to healthy ageing. The participant data and faecal samples were collected from these two groups and the microbiota was whole-genome sequenced and taxonomically classified with MetaPhlAn. RESULTS: The physically active senior orienteers had a more homogeneous microbiota within the group and a higher abundance of Faecalibacterium prausnitzii compared to the community-dwelling older adults. Faecalibacterium prausnitzii has previously shown to have beneficial properties. Senior orienteers also had a lower abundance of Parasutterella excrementihominis and Bilophila unclassified, which have been associated with impaired GI health. We could not observe any difference between the groups in terms of Shannon diversity index. Interestingly, a subgroup of community-dwelling older adults showed an atypical microbiota profile as well as the parameters for gastrointestinal symptoms and well-being closer to senior orienteers. CONCLUSIONS: Our results suggest specific composition characteristics of healthy microbiota in the elderly, and show that certain components of nutrition as well as psychological distress are not as tightly connected with composition or diversity variation in faecal microbiota samples.