Probiotics and dietary counselling contribute to glucose regulation during and after pregnancy: a randomised controlled trial. Br J Nutr. 2009;101:1679-1687. [PMID: 19017418 DOI: 10.1017/s0007114508111461]

Of the bugs that shape us: maternal obesity, the gut microbiome, and long-term disease risk

Chronic disease risk is inextricably linked to our early-life environment, where maternal, fetal, and childhood factors predict disease risk later in life. Currently, maternal obesity is a key predictor of childhood obesity and metabolic complications in adulthood. Although the mechanisms are unclear, new and emerging evidence points to our microbiome, where the bacterial composition of the gut modulates the weight gain and altered metabolism that drives obesity. Over the course of pregnancy, maternal bacterial load increases, and gut bacterial diversity changes and is influenced by pre-pregnancy- and pregnancy-related obesity. Alterations in the bacterial composition of the mother have been shown to affect the development and function of the gastrointestinal tract of her offspring. How these microbial shifts influence the maternal-fetal-infant relationship is a topic of hot debate. This paper will review the evidence linking nutrition, maternal obesity, the maternal gut microbiome, and fetal gut development, bringing together clinical observations in humans and experimental data from targeted animal models.

Effects of 12 weeks of treatment with fermented milk on blood pressure, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind placebo-controlled study

OBJECTIVE

Studies have indicated a blood pressure (BP)-lowering effect of milk-derived peptides in non-diabetic individuals, but the cardiometabolic effects of such peptides in patients with type 2 diabetes (T2D) are not known. We investigated the effect of milk fermented with Lactobacillus helveticus on BP, glycaemic control and cardiovascular risk factors in T2D.

DESIGN

A randomised, double-blinded, prospective, placebo-controlled study.

METHODS

In one arm of a factorial study design, 41 patients with T2D were randomised to receive 300 ml milk fermented with L. helveticus (Cardi04 yogurt) (n=23) or 300 ml artificially acidified milk (placebo yogurt) (n=18) for 12 weeks. BPs were measured over 24-h, and blood samples were collected in the fasting state and during a meal test before and after the intervention.

RESULTS

Cardi04 yogurt did not reduce 24-h, daytime or nighttime systolic or diastolic BPs compared with placebo (P>0.05). Daytime and 24-h heart rate (HR) were significantly reduced in the group treated by Cardi04 yogurt compared with the placebo group (P<0.05 for both). There were no differences in HbA1c, plasma lipids, C-reactive protein, plasminogen activator inhibitor-1, tumour necrosis factor alpha, tissue-type plasminogen activator: Ag, and von Willebrand factor: Ag between the groups. The change in fasting blood glucose concentration differed significantly between the two groups with a larger increase in the placebo group (P<0.05).

CONCLUSIONS

Ingestion of milk fermented with L. helveticus compared with placebo for 12 weeks did not significantly reduce BP in patients with T2D. Our finding of lower HRs and fasting plasma glucose levels in T2D patients during ingestion of fermented milk needs further validation.

Living ordinary family life with an allergic child-the mother's perspective

Ecocultural theory considering family as an entity may serve as a new point of view instead of "impact of disease"-perspective. Aims were to reveal ecocultural themes and activities of daily routines in the treatment of a child's food allergy and eczema. Interviews (N=24) were held with mothers with allergic children aged 12 months and mothers repeat interviews at 24 months. The theme; "living an ordinary family life", was implemented across the family activities of routines essential for treating the child's allergy. New or altered treatment regimens can be tailored to families on the basis of existing activities.

Modulation of the gut microbiota by nutrients with prebiotic and probiotic properties

Experimental data in animals, but also observational studies in humans, suggest that the composition of the gut microbiota differs in obese vs. lean individuals, in patients with vs. without diabetes, or in patients presenting other diseases associated with obesity or nutritional disbalance, such as non-alcoholic fatty liver disease (NAFLD) or cardiovascular diseases. In this review, we describe how changes in the composition and/or activity of the gut microbiota by administration of nutrients with probiotic or prebiotic properties can modulate host gene expression and metabolism and thereby positively influence host adipose tissue development and related metabolic disorders.

NOD1 expression is increased in the adipose tissue of women with gestational diabetes

Maternal peripheral insulin resistance and increased inflammation are two features of pregnancies, complicated by gestational diabetes mellitus (GDM). The nucleotide-binding oligomerisation domain (NOD) intracellular molecules recognise a wide range of microbial products, as well as other intracellular danger signals, thereby initiating inflammation through activation of nuclear factor κB (NFκB). The aim of this study was to determine whether levels of NOD1 and NOD2 are increased in adipose tissue of women with GDM. The effect of NOD1 and NOD2 activation on inflammation and the insulin signalling pathway was also assessed. NOD1, but not NOD2, expression was higher in omental and subcutaneous adipose tissues obtained from women with GDM when compared with those from women with normal glucose tolerance (NGT). In both omental and subcutaneous adipose tissues from NGT and GDM women, the NOD1 ligand g-d-glutamyl-meso-diaminopimelic acid (iE-DAP) significantly induced the expression and secretion of the pro-inflammatory cytokine interleukin 6 (IL6) and chemokine IL8; COX2 (PTGS2) gene expression and subsequent prostaglandin production; the expression and secretion of the extracellular matrix remodelling enzyme matrix metalloproteinase 9 (MMP9) and the gene expression and secretion of the adhesion molecules ICAM1 and VCAM1. There was no effect of the NOD2 ligand muramyl dipeptide on any of the endpoints tested. The effects of the NOD1 ligand iE-DAP were mediated via NFκB, as the NFκB inhibitor BAY 11-7082 significantly attenuated iE-DAP-induced expression and secretion of pro-inflammatory cytokines, COX2 gene expression and subsequent prostaglandin production, MMP9 expression and secretion and ICAM1 and VCAM1 gene expression and secretion. In conclusion, the present findings describe an important role for NOD1 in the development of insulin resistance and inflammation in pregnancies complicated by GDM.

Gut microbiota, probiotics and diabetes

Diabetes is a condition of multifactorial origin, involving several molecular mechanisms related to the intestinal microbiota for its development. In type 2 diabetes, receptor activation and recognition by microorganisms from the intestinal lumen may trigger inflammatory responses, inducing the phosphorylation of serine residues in insulin receptor substrate-1, reducing insulin sensitivity. In type 1 diabetes, the lowered expression of adhesion proteins within the intestinal epithelium favours a greater immune response that may result in destruction of pancreatic β cells by CD8+ T-lymphocytes, and increased expression of interleukin-17, related to autoimmunity. Research in animal models and humans has hypothesized whether the administration of probiotics may improve the prognosis of diabetes through modulation of gut microbiota. We have shown in this review that a large body of evidence suggests probiotics reduce the inflammatory response and oxidative stress, as well as increase the expression of adhesion proteins within the intestinal epithelium, reducing intestinal permeability. Such effects increase insulin sensitivity and reduce autoimmune response. However, further investigations are required to clarify whether the administration of probiotics can be efficiently used for the prevention and management of diabetes.

Probiotics in obese pregnancy do not reduce maternal fasting glucose: a double-blind, placebo-controlled, randomized trial (Probiotics in Pregnancy Study)

BACKGROUND

Recent studies have reported beneficial effects of probiotics on maternal glycemia in healthy pregnant women. Obesity significantly increases risk of impaired glucose tolerance in pregnancy, but glycemic effects of probiotics in this specific obstetric group require additional investigation.

OBJECTIVE

The aim of the Probiotics in Pregnancy Study was to investigate the effect of a probiotic capsule on maternal fasting glucose in obese pregnant women.

DESIGN

In this placebo-controlled, double-blind, randomized trial, 175 pregnant women with an early pregnancy body mass index (BMI; in kg/m²) from 30.0 to 39.9 were recruited from antenatal clinics at the National Maternity Hospital, Dublin, Ireland. Exclusion criteria were BMI <30.0 or >39.9, prepregnancy or gestational diabetes, age <18 y, multiple pregnancy, and fetal anomaly. Women were randomly assigned to receive either a daily probiotic or a placebo capsule from 24 to 28 wk of gestation in addition to routine antenatal care. The primary outcome was the change in fasting glucose between groups from preintervention to postintervention. Secondary outcomes were the incidence of gestational diabetes and neonatal anthropometric measures.

RESULTS

In 138 women who completed the study (63 women in the probiotic group; 75 women in the placebo group), mean (±SD) early pregnancy BMI was 33.6 ± 2.6, which differed significantly between probiotic (32.9 ± 2.4) and placebo (34.1 ± 2.7) groups. With adjustment for BMI, the change in maternal fasting glucose did not differ significantly between treated and control groups [-0.09 ± 0.27 compared with -0.07 ± 0.39 mmol/L; P = 0.391; B = -0.05 (95% CI: -0.17, 0.07)]. There were also no differences in the incidence of impaired glycemia (16% in the probiotic group compared with 15% in the placebo group; P = 0.561), birth weight (3.70 kg in the probiotic group compared with 3.68 kg in the placebo group; P = 0.723), or other metabolic variables or pregnancy outcomes. A secondary analysis of 110 women, excluding antibiotic users and poor compliers, also revealed no differences in maternal glucose or other outcomes between groups.

CONCLUSION

Probiotic treatment of 4 wk during pregnancy did not influence maternal fasting glucose, the metabolic profile, or pregnancy outcomes in obese women.

Probiotics for preventing gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a range of adverse pregnancy outcomes for mother and infant. The prevention of GDM using lifestyle interventions has proven difficult. The gut microbiome (the composite of bacteria present in the intestines) influences host inflammatory pathways, glucose and lipid metabolism and, in other settings, alteration of the gut microbiome has been shown to impact on these host responses. Probiotics are one way of altering the gut microbiome but little is known about their use in influencing the metabolic environment of pregnancy.

OBJECTIVES

To assess the effects of probiotic supplementation when compared with other methods for the prevention of GDM.

SEARCH METHODS

We searched the Cochrane Pregnancy and childbirth Group's Trials Register (31 August 2013) and reference lists of the articles of retrieved studies.

SELECTION CRITERIA

Randomised and cluster-randomised trials comparing the use of probiotic supplementation with other methods for the prevention of the development of GDM. Cluster-randomised trials were eligible for inclusion but none were identified. Quasi-randomised and cross-over design studies are not eligible for inclusion in this review. Studies presented only as abstracts with no subsequent full report of study results would also have been excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed risk of bias of included study. Data were checked for accuracy.

MAIN RESULTS

Eleven reports (relating to five possible trials) were found. We included one study (six trial reports) involving 256 women. Four other studies are ongoing.The included trial consisted of three treatment arms: probiotic with dietary intervention, placebo and dietary intervention, and dietary intervention alone; it was at a low risk of bias. The study reported primary outcomes of a reduction in the rate of gestational diabetes mellitus (risk ratio (RR) 0.38, 95% confidence interval (CI) 0.20 to 0.70), with no statistical difference in the rates of miscarriage/intrauterine fetal death (IUFD)/stillbirth/neonatal death (RR 2.00, 95% CI 0.35 to 11.35). Secondary outcomes reported were a reduction in infant birthweight (mean difference (MD) -127.71 g, 95% CI -251.37 to -4.06) in the probiotic group and no clear evidence of increased risk of preterm delivery (RR 3.27, 95% CI 0.44 to 24.43), or caesarean section rate (RR 1.23, 95% CI 0.65 to 2.32). The primary infant outcomes of rates of macrosomia and large-for-gestational age infants were not reported. The following secondary outcomes were not reported: maternal gestational weight gain, pre-eclampsia, and the long-term diagnosis of diabetes mellitus; infant body composition, shoulder dystocia, admission to neonatal intensive care, jaundice, hypoglycaemia and long-term rates of obesity and diabetes mellitus.

AUTHORS' CONCLUSIONS

One trial has shown a reduction in the rate of GDM when women are randomised to probiotics early in pregnancy but more uncertain evidence of any effect on miscarriage/IUFD/stillbirth/neonatal death. There are no data on macrosomia. At this time, there are insufficient studies to perform a quantitative meta-analysis. Further results are awaited from four ongoing studies.

The effects of probiotic bacteria on glycaemic control in overweight men and women: a randomised controlled trial

BACKGROUND/OBJECTIVES

Evidence from animal and in vitro models suggest a role of probiotic bacteria in improving glycaemic control and delaying the onset of type 2 diabetes. However, the evidence from controlled trials in humans is limited. The objective was to determine if the probiotic bacteria L. acidophilus La5 and B. animalis subsp lactis Bb12, supplemented in a whole food (yoghurt) or isolated (capsules) form, can improve biomarkers of glycaemic control.

SUBJECTS/METHODS

Following a 3-week washout period, 156 overweight men and women over 55 years (mean age: 67 ± 8 years; mean body mass index (31 ± 4 kg/m(2)) were randomized to a 6-week double-blinded parallel study. The four intervention groups were: (A) probiotic yoghurt plus probiotic capsules; (B) probiotic yoghurt plus placebo capsules; (C) control milk plus probiotic capsules; and (D) control milk plus placebo capsules. Outcome measurements, including fasting glucose, insulin, glycated haemoglobin and Homoeostasis Model Assessment of Insulin Resistance (HOMA-IR), were performed at baseline and week 6.

RESULTS

Relative to the milk-control group, probiotic yoghurt resulted in a significantly higher HOMA-IR (0.32 ± 0.15, P=0.038), but did not have a significant effect on the other three measures of glycaemic control (P>0.05). Relative to placebo capsules, probiotic capsules resulted in a significantly higher fasting glucose (0.15 ± 0.07 mmol/l, P=0.037), with no significant effect on the other three measures of glycaemic control (P>0.05). Further analyses did not identify other variables as contributing to these adverse findings.

CONCLUSIONS

Data from this study does not support the hypothesis that L. acidophilus La5 and B. animalis subsp lactis Bb12, either in isolated form or as part of a whole food, benefit short-term glycaemic control. Indeed, there is weak data for an adverse effect of these strains on glucose homoeostasis.

Benefits of repeated individual dietary counselling in long-term weight control in women after delivery

As pregnancy may trigger overweight in women, new means for its prevention are being sought. The aim here was to investigate the effect of individual dietary counselling during and after pregnancy on post-partum weight and waist circumference up to 4 years post-partum. A cohort of women (n = 256) were randomized to receive repeated individual dietary counselling by a nutritionist during and after pregnancy, or as controls not receiving dietary counselling, from the first trimester of pregnancy until 6 months after delivery. Counselling aimed to bring dietary intake into line with recommendations, with particular focus on the increase in the intake of unsaturated fatty acids instead of saturated. Pre-pregnancy weight was taken from welfare clinic records. Weight and waist circumference were measured at 4 years after delivery. The proportion of overweight women increased from 26% prior to pregnancy to 30% at 4 years after delivery among women receiving dietary counselling, as against considerably more, from 32% to 57%, among controls. The prevalence of central adiposity was 31% in women receiving dietary counselling, 64% in controls. Likewise, both the risk of overweight (odds ratio: 0.23, 0.08-0.63, P = 0.005) and central adiposity (odds ratio: 0.18, 0.06-0.52, P = 0.002) were lower in women receiving dietary counselling compared with controls. Repeated dietary counselling initiated in early pregnancy can be beneficial in long-term weight control after delivery.

A systematic review of the safety of probiotics

INTRODUCTION

There is growing evidence on the use of probiotics in various diseases, especially in gastrointestinal (GI) diseases. Although probiotics have been found helpful in many illnesses, they do not always seem to be safe. Through interference with commensal microflora, they can result in opportunistic performances in the host due to bacterimia and fungemia. Since considerable numbers of consumers use probiotic products worldwide, assurance of safety of these products is necessary.

AREAS COVERED

This review evaluates all the existing information about the safety of probiotics in humans and animal models up to May 2013. In all eligible published studies in which adverse effects and tolerability of probiotics were investigated and reported, no language limitations were applied. The main key search terms were 'probiotics,' 'safety,' 'side effects,' 'clinical trial' and 'adverse effects.' The vast majority of trials investigated Bifidobacterium (B) and Lactobacillus (L) species.

EXPERT OPINION

The main observed adverse effects of probiotics were sepsis, fungemia and GI ischemia. Generally, critically ill patients in intensive care units, critically sick infants, postoperative and hospitalized patients and patients with immune-compromised complexity were the most at-risk populations. While the overwhelming existing evidence suggests that probiotics are safe, complete consideration of risk-benefit ratio before prescribing is recommended.

The role of lifestyle interventions in the prevention of gestational diabetes

Gestational diabetes is associated with adverse pregnancy outcomes, increased costs, and long-term risk of type 2 diabetes mellitus (T2DM) in the mother. Observational data have shown an association between reduced weight gain, healthy eating, and physical activity and reduced rates of gestational diabetes mellitus (GDM). Despite this, most randomized controlled trials of lifestyle interventions to prevent GDM have been negative. Dietary approaches appear to be more successful than exercise or a combination of diet and exercise at decreasing GDM. Reasons for negative studies may include lack of power, lack of intervention uptake, and severity of placenta mediated insulin resistance. Future studies should be powered for a reduction in GDM, monitor lifestyle changes closely, and include a psychological component in the intervention.

Maternal and in utero determinants of type 2 diabetes risk in the young

The global prevalence of diabetes mellitus has reached epidemic proportions. In 2010, it was estimated that 6.4 % of the adult population (285 million) have diabetes. In recent years, the incidence of type 2 diabetes (T2D), a condition traditionally associated with aging, has been steadily increasing among younger individuals. It is now a well-established notion that the early-life period is a critical window of development and that influences during this period can "developmentally prime" the metabolic status of the adult. This review discusses the role of maternal and in utero influences on the developmental priming of T2D risk. Both human epidemiological studies and experimental animal models are beginning to demonstrate that early dietary challenges can accelerate the onset of age-associated metabolic disturbances, including insulin resistance, T2D, obesity, hypertension, and cardiovascular disease. These findings show that poor maternal nutrition can prime a prediabetes phenotype, often manifest as insulin resistance, by very early stages of life. Thus, the maternal diet is a critical determinant of premature T2D risk. While the mechanisms that link early nutrition to age-associated metabolic decline are currently unclear, preliminary findings suggest perturbations in a number of processes involved in cellular aging, such as changes in longevity-associated Sirtuin activity, epigenetic regulation of key metabolic genes, and mitochondrial dysfunction. Preliminary studies show that pharmacological interventions in utero and dietary supplementation in early postnatal life may alleviate insulin resistance and reduce T2D risk. However, further studies are warranted to fully understand the relationship between the early environment and long-term effects on metabolism. Such mechanistic insights will facilitate strategic interventions that prevent accelerated metabolic decline and the premature onset of T2D in the current and future generations.

The role of probiotics and prebiotics in inducing gut immunity

The gut immune system is influenced by many factors, including dietary components and commensal bacteria. Nutrients that affect gut immunity and strategies that restore a healthy gut microbial community by affecting the microbial composition are being developed as new therapeutic approaches to treat several inflammatory diseases. Although probiotics (live microorganisms) and prebiotics (food components) have shown promise as treatments for several diseases in both clinical and animal studies, an understanding of the molecular mechanisms behind the direct and indirect effects on the gut immune response will facilitate better and possibly more efficient therapy for diseases. In this review, we will first describe the concept of prebiotics, probiotics, and symbiotics and cover the most recently well-established scientific findings regarding the direct and indirect mechanisms by which these dietary approaches can influence gut immunity. Emphasis will be placed on the relationship of diet, the microbiota, and the gut immune system. Second, we will highlight recent results from our group, which suggest a new dietary manipulation that includes the use of nutrient products (organic selenium and Lithothamnium muelleri) and probiotics (Saccharomyces boulardii UFMG 905 and Bifidobacterium sp.) that can stimulate and manipulate the gut immune response, inducing intestinal homeostasis. Furthermore, the purpose of this review is to discuss and translate all of this knowledge into therapeutic strategies and into treatment for extra-intestinal compartment pathologies. We will conclude by discussing perspectives and molecular advances regarding the use of prebiotics or probiotics as new therapeutic strategies that manipulate the microbial composition and the gut immune responses of the host.

Related actions of probiotics and antibiotics on gut microbiota and weight modification

Antibiotics and probiotics are widely used as growth promoters in agriculture. Most antibiotics prescribed in clinical practice are natural products that originate from Streptomyces spp, which were first used as agricultural probiotics. Antibiotics and probiotics both modify the gut microbiota. The effect of a probiotic species on the digestive flora depends on the strain and is largely determined by bacteriocin production. In human beings, as in animals, specific probiotics are associated with weight gain or loss. Improved understanding of the ability of specific probiotics to harvest energy from the host diet might lead to development of new treatments for obesity and malnutrition. In this Review, we present the effects of probiotics and antibiotics on the gut microbiota of human beings and animals and discuss their potential therapeutic use as interventions for weight gain and loss in human beings.

Maternal dietary counseling reduces total and LDL cholesterol postpartum

OBJECTIVE

The aim of this study was to investigate the effects of dietary counseling on blood lipid concentrations during and after pregnancy.

METHODS

Partcipants (N = 256) were randomized into three study groups: dietary counseling with probiotics or placebo and a control group at first trimester of pregnancy. Diet quality was evaluated from food records by an index of healthy eating and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, apolipoproteins A-I and B, and lipoprotein (a) were measured at the first and third trimesters of pregnancy and 1, 6, and 12 mo postpartum.

RESULTS

During pregnancy, no differences in lipid values were noted among the groups, but postpartum TC and LDL-C were lower in both dietary counseling groups compared with controls (P = 0.027 and P = 0.012, respectively). Higher points on the healthy eating index, normal weight, and regular exercise were associated with a more favorable lipid profile at 12 mo after delivery.

CONCLUSION

Maternal dietary counseling may lower maternal TC and LDL-C levels postpartum. A healthy lifestyle during pregnancy and postpartum may benefit women's cardiovascular health.

Diet and blood lipids in 1-4 year-old children

BACKGROUND AND AIM

Early nutrition may programme blood lipid levels and thereby later cardiovascular health of children. The objective here was to evaluate the effects of maternal dietary counselling during pregnancy and breastfeeding on dietary intakes and blood lipid values in 1-4 year-old children. Further, the nutritional determinants of children's lipid profiles were assessed.

METHODS AND RESULTS

Mothers were randomised into dietary counselling or control groups at the first trimester of pregnancy. Their children were followed up clinically at 1, 2 and 4 years of age, by three-day food records and analyses of total cholesterol, HDL cholesterol and apolipoproteins A-I and B as well as lipoprotein (a). In general, the mean intake of saturated fatty acids as a proportion of total energy intake (E%) was higher than the recommended, while the mean intake of polyunsaturated fatty acids was low in children's diet. Over the first years, girls had higher concentration of non-HDL cholesterol than boys; 2.64 mmol/l (95% CI 2.54-2.74) vs. 2.49 (2.38-2.60); p = 0.038. Maternal dietary counselling was not reflected in the children's lipid values. Children's monounsaturated fatty acid intake (E%) correlated with apoA-I (p = 0.048) and, furthermore, there was a negative correlation between polyunsaturated fatty acid intake (E%) and apoB (p = 0.046).

CONCLUSION

Children's dietary fatty acid intake, but not maternal dietary counselling was shown to be related to blood apolipoproteins in children.

Perinatal outcomes of prenatal probiotic and prebiotic administration: an integrative review

The purpose of this integrative review was to identify, critique, and synthesize the maternal and neonatal evidence on the prenatal use of probiotics and prebiotics to inform perinatal health professionals. A comprehensive literature search resulted in 37 studies of prenatal probiotics and 1 on antepartal prebiotics published from 1990 through 2011 that reported maternal, fetal, and/or neonatal outcomes. The methodologic quality of the studies reviewed was high, although investigators used different probiotic combinations and inconsistently reported perinatal clinical outcomes. The extraction of perinatal outcome variables resulted in identification of 9 maternal and 5 neonatal categories. Prenatal probiotics significantly reduced the incidence of bacterial vaginosis, increased colonization with vaginal Lactobacillus and intestinal Lactobacillus rhamnosus, altered immune markers in serum and breast milk, improved maternal glucose metabolism, and reduced the incidence of gestational diabetes and preeclampsia. Antepartally, probiotics were associated with significantly higher counts of Bifidobacterium and Lactococcus lactis (healthy intestinal flora) in neonatal stool. Prenatal prebiotics significantly increased maternal intestinal Bifidobacterium. No adverse events were reported and there was evidence of safety and tolerance of prenatal probiotics and prebiotics in the scientific investigations reviewed. It is recommended that in future investigations of prenatal probiotics researchers explicitly report maternal and neonatal outcomes.

Nutritional programming of insulin resistance: causes and consequences

Strong evidence indicates that adverse prenatal and early postnatal environments have a significant long-term influence on risk factors that result in insulin resistance, type 2 diabetes (T2D), and cardiovascular disease later in life. Here we discuss current knowledge of how maternal and neonatal nutrition influence early growth and the long-term risk of developing insulin resistance in different organs and at the whole-body level. Accumulating evidence supports a role for epigenetic mechanisms underlying this nutritional programming, consisting of heritable changes that regulate gene expression which in turn shapes the phenotype across generations. Deciphering these molecular mechanisms in key tissues and discovering key biological markers may provide valuable insight towards the development of effective intervention strategies.

Oral Lactobacillus reuteri GMN-32 treatment reduces blood glucose concentrations and promotes cardiac function in rats with streptozotocin-induced diabetes mellitus

Impaired regulation of blood glucose levels in diabetes mellitus (DM) patients and the associated elevation of blood glucose levels are known to increase the risk of diabetic cardiomyopathy (DC). In the present study, a probiotic bacterium, Lactobacillus reuteri GMN-32, was evaluated for its potential to reduce blood glucose levels and to provide protection against DC risks in streptozotocin (STZ)-induced DM rats. The blood glucose levels of the STZ-induced DM rats when treated with L. reuteri GMN-32 decreased from 4480 to 3620 mg/l (with 10⁷ colony-forming units (cfu)/d) and 3040 mg/l (with 10⁹ cfu/d). Probiotic treatment also reduced the changes in the heart caused by the effects of DM. Furthermore, the Fas/Fas-associated protein with death domain pathway-induced caspase 8-mediated apoptosis that was observed in the cardiomyocytes of the STZ-induced DM rats was also found to be controlled in the probiotic-treated rats. The results highlight that L. reuteri GMN-32 treatment reduces blood glucose levels, inhibits caspase 8-mediated apoptosis and promotes cardiac function in DM rats as observed from their ejection fraction and fractional shortening values. In conclusion, the administration of L. reuteri GMN-32 probiotics can regulate blood glucose levels, protect cardiomyocytes and prevent DC in DM rats.

Perinatal nutrition programs neuroimmune function long-term: mechanisms and implications

Our early life nutritional environment can influence several aspects of physiology, including our propensity to become obese. There is now evidence to suggest perinatal diet can also independently influence development of our innate immune system. This review will address three not-necessarily-exclusive mechanisms by which perinatal nutrition can program neuroimmune function long-term: by predisposing the individual to obesity, by altering the gut microbiota, and by inducing epigenetic modifications that alter gene transcription throughout life.

Relevance of pre- and postnatal nutrition to development and interplay between the microbiota and metabolic and immune systems

Early-life programming is becoming an established concept that states that the environment during early development affects health and disease in adulthood, probably via epigenetic mechanisms such as DNA methylation, histone modifications, RNA silencing, or a combination. Accumulating evidence suggests that nutrition during pregnancy and early postnatal life is one of the most important environmental cues that programs microbiological, metabolic, and immunologic development. The neonatal period is crucial for the early microbial colonization of the almost sterile gastrointestinal tract of the newborn infant. These first colonizers play an important role in host health because they are involved in nutritional, immunologic, and physiologic functions. Evidence from animal and human studies indicates that the composition of the gut microbiota has an effect on body composition, digestion, and metabolic homeostasis. Furthermore, the functionality of the metabolism develops after birth when the newborn is first exposed to nutrition via the gastrointestinal tract. Exposure to environmental microbial components is also suggested to have a key role in the maturation process of the immune system, and in turn the immune system shapes the composition of the microbiota. Therefore, the use of nutritional strategies to program the microbiota composition to favor a more beneficial bacterial population and to support the development of the metabolic and immune systems may provide a good opportunity to prevent later health problems such as obesity, diabetes, and allergy.

Role of the Nutrition Professional: In High-risk Obstetrics Inpatient Teams

Beyond the management of gestational diabetes and weight control, limited literature exists on nutritional management in high-risk pregnancies. This study is a starting point for understanding the role of the registered dietitian (RD) in high-risk obstetrics (HRO) inpatient teams. Demographic information was gathered on Ontario HRO inpatient units and patient characteristics, and the RD’s role in this setting was explored. Representatives from all six HRO units in Ontario completed a questionnaire. Five of the HRO units had an RD on the team. The RDs stated that their primary role in the unit involved providing nutrition education and support, screening patients for nutritional risk, and writing vitamin and mineral orders. This was the first study in which RDs’ role in HRO inpatient units was examined. Existing literature supports the role of good nutrition in preventing and treating the conditions seen in HRO units; however, RDs’ specific role remains unclear. Future studies are needed to analyze the effect of nutrition on these HRO conditions, and to support the development of best practice guidelines.

Weight status and dietary intake determine serum leptin concentrations in pregnant and lactating women and their infants

Leptin regulates energy homeostasis and immune and metabolic functions. Highly elevated leptin concentrations during pregnancy may be associated with aberrations in maternal metabolism and long-term health consequences both in women and children. The objective of the present study was to evaluate whether dietary counselling, probiotic supplementation, maternal characteristics or dietary intake during pregnancy has an impact on serum leptin concentrations in women, cord blood or in children. A total of 256 pregnant women were randomised to a control group (n 85) or to receive dietary counselling with probiotics (n 85) or placebo (n 86). Dietary counselling aimed at affecting the type of fat used and to increase the amount of fibre in the women's diet. Women's dietary intake and serum leptin concentrations were analysed at the first and third trimesters of pregnancy and at 1 month postpartum. Furthermore, leptin concentrations were measured from the cord blood and from children's serum at 1 and 6 months of age. Weight status and dietary composition were the key determinants of leptin concentrations. Specifically, high dietary fibre and low SFA intakes were related to low serum leptin concentrations in women. Female sex and birth weight were associated with higher infant leptin, whereas cord blood leptin was additionally affected by maternal leptin concentration and protein intake. Probiotics or dietary counselling did not affect leptin concentrations. Weight control to recommended levels and modification of diet towards higher fibre and lower SFA intakes during pregnancy may through leptin concentrations provide health benefits to both women and children.

The impact of dietary counselling during pregnancy on vitamin intake and status of women and their children

We aimed here to assess the impact of dietary counselling during pregnancy on dietary intake of vitamins and the vitamin status of women and their children. At the first trimester of pregnancy, 89 women from allergic families were randomized to a control group (n = 45) or to receive individual dietary counselling (n = 44). Women's vitamin intakes and serum concentrations were analyzed during and after pregnancy. Further, vitamin concentrations were measured from breast milk and infant serum at one month of age. The study is registered as clinical study (NCT00167000; section 3, http://www.clinicaltrials.gov ). Dietary counselling resulted in a higher intake of beta-carotene and vitamin E compared to controls. Further, in women lower serum beta-carotene and higher colostrum vitamin A concentrations were found in the intervention group compared to controls. Dietary counselling during pregnancy improves women's vitamin intakes but does not provide unambiguous effects on vitamin status of women or children.

Perinatal pet exposure, faecal microbiota, and wheezy bronchitis: is there a connection?

Background. The hygiene hypothesis suggests that high hygiene standards have led to an immune dysfunction and an increase in allergic diseases. Farming-related exposures are associated with a decreased risk of asthma. Since the gut microbiota may be a pivotal component in the hygiene hypothesis, we studied whether perinatal exposure to pets, doctor's diagnosed wheezy bronchitis (WB), and compositional changes in the gut microbiota are interrelated among urban infants. Methods. Data were collected prospectively from a mother-infant nutrition study. Data on perinatal pet ownership, WB, and the microbiota composition of faecal samples of the infants assessed by quantitative PCR at 1 month were compared. Results. None of the 30 infants exposed to pets had suffered from WB by 24 months, whereas 15 of the 99 (15%) nonexposed infants had had WB (P = 0.03). The counts of Bifidobacterium longum were higher in samples (n = 17) from nonwheezing infants with pet exposure compared to those (n = 10) in wheezing infants without pet exposure (8.59/10.44 versus 5.94/9.86, resp. (median/upper limit of range, bacteria(log)/g of stool); P = 0.02). B. breve was more abundant in the wheezing infants (P = 0.02).

Probiotics: a potential role in the prevention of gestational diabetes?

The gut microbiome has a complex relationship with host metabolism and immune function. Host health and diet influence the composition of the gut microbiome, and conversely, different microbiome compositions influence host metabolism. Gestational diabetes mellitus is increasingly common and has serious implications for maternal and foetal health both during pregnancy and later in life. To date, clinical trials of exercise and dietary interventions to prevent the onset of gestational diabetes have had heterogeneous results and have proven disappointingly difficult. Alternative prevention strategies of gestational diabetes mellitus need to be considered and trialled in a placebo-controlled manner in combination with dietary and behavioural measures. One such potential preventative therapy is probiotic supplementation, that is, ingestion of specific bacterial strains with beneficial effects on the host. Probiotic supplements have been shown to improve metabolism by increasing host insulin sensitivity, cholesterol metabolism and also have a beneficial effect on the immune system. This discussion paper examines the evidence for the influence of the gut microbiome on host metabolism and the potential metabolic impact of probiotic supplementation, with particular regard for the evidence surrounding a possible use of probiotic supplements for the prevention of gestational diabetes. Probiotics offer the tantalising possibility of a feasible intervention for the prevention of gestational diabetes and improvement of metabolic syndromes, but there is a pressing need for further studies of the mechanisms underlying the apparent metabolic benefits and for the use of randomised controlled trials to allow examination of the effectiveness of probiotic supplementation in this setting.

Probiotics to adolescents with obesity: effects on inflammation and metabolic syndrome

OBJECTIVES

The connections between gut microbiota, energy homeostasis, and inflammation and its role in the pathogenesis of obesity-related disorders are increasingly recognized. We aimed to investigate the effect of the probiotic strain Lactobacillus salivarius Ls-33 on a series of biomarkers related to inflammation and the metabolic syndrome (MS) in adolescents with obesity.

METHODS

The study was a double-blind placebo-controlled trial including 50 adolescents with obesity randomized to Ls-33 (10 CFU) or placebo daily for 12 weeks.

RESULTS

The average body mass index-for-age z-score was 2.6 ± 0.5. There were no differences in biomarkers of inflammation and parameters related to the MS at baseline between the probiotic and placebo groups. Furthermore, there were no differences in changes from baseline to 12-week intervention with regard to any anthropometric measures, blood pressure (systolic and diastolic), fasting glucose and insulin, homeostasis model assessment of insulin resistance, C-peptide, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, free fatty acids, C-reactive protein, interleukin-6, tumor necrosis factor alpha, or fecal calprotectin, despite the increased values of biomarkers of inflammation and of several parameters related to the MS at baseline when compared with normal-weight adolescents. The levels of L salivarius in fecal samples from the probiotic group in the present study were comparable with the levels reported for the other probiotic lactobacilli and bifidobacteria using quantitative polymerase chain reaction.

CONCLUSIONS

It was not possible to detect any beneficial effect of the probiotic intervention with Ls-33 on inflammatory markers or parameters related to the MS in adolescents with obesity being in a state of low-grade systemic inflammation.

Understanding the role of gut microbes and probiotics in obesity: how far are we?

Obesity has been associated with structural alterations in the gut microbiota, suggesting potential causality between specific microbial taxa and this disorder. Studies in animal models have also provided evidence for plausible gut microbiota mechanisms of action underlying body weight regulation. Yet evidence identifying which specific microbes contribute to or predict obesity is not completely consistent across studies. More recently, diet has also been shown to be primarily involved in regulating the microbiota structure initially related to obesity, suggesting that the role of microbes in energy balance is under the influence of diet. Controversy over the role of components of the gut microbiota in obesity has extended to bacteria, which although weakly related to body weight in observational and human intervention studies, are of interest due to their use as probiotics. This review focuses exclusively on human observational studies and probiotic intervention trials, excluding animal studies and studies in infants at early developmental stages, since such results cannot be extrapolated to human obesity at later stages in life. In this context, evidence for relationships between the gut microbiota composition and obesity and the possible role of probiotics is reviewed, discussing the strengths and weaknesses of the studies conducted to date.

Can nutritional modulation of maternal intestinal microbiota influence the development of the infant gastrointestinal tract?

The gastrointestinal microbiota plays an important role in maintaining host health by preventing the colonization of pathogens, fermenting dietary compounds, and maintaining normal mucosal immunity. Particularly in early life, the composition of the microbiota profoundly influences the development and maturation of the gastrointestinal tract (GIT) mucosa, which may affect health in later life. Therefore, strategies to manipulate the microbiota during infancy may prevent the development of some diseases later in adult life. Earlier research suggested that term fetuses are sterile and that the initial bacterial colonization of the newborn GIT occurs only after the baby transits through the birth canal. However, recent studies have demonstrated that the colonization and/or contact of the fetus with the maternal GIT microbiota may start in utero. After vaginal birth, the colonization of the neonate GIT continues through contact with maternal feces and vaginal bacteria, leading to a relatively simple microbial community that is influenced by feeding type (breast vs. formula feeding). Maternal GIT microbiota, vaginal microbiota, and breast milk composition are influenced by maternal diet. Alterations of the maternal GIT microbiota composition via supplementation with probiotics and prebiotics have been shown; however, transfer of these benefits to the offspring remains to be demonstrated. This review focuses on the influence of maternal GIT microbiota during the pre- and postpartum periods on the colonization of the infant GIT. In particular, it examines the manipulation of the maternal GIT microbiota composition through the use of probiotics and/or prebiotics and subsequent consequences for the health of the offspring.

Microbial contact during pregnancy, intestinal colonization and human disease

Interaction with colonizing intestinal bacteria is essential for healthy intestinal and immunological development in infancy. Advances in understanding early host-microbe interactions indicate that this early microbial programming begins in utero and is substantially modulated by mode of birth, perinatal antibiotics and breastfeeding. Furthermore, it has become evident that this stepwise microbial colonization process, as well as immune and metabolic programming by the microbiota, might have a long-lasting influence on the risk of not only gastrointestinal disease, but also allergic, autoimmune and metabolic disease, in later life. Modulating early host-microbe interaction by maternal probiotic intervention during pregnancy and breastfeeding offers a promising novel tool to reduce the risk of disease. In this Review, we describe the current body of knowledge regarding perinatal microbial contact, initial intestinal colonization and its association with human disease, as well as means of modulating early host-microbe interaction to reduce the risk of disease in the child.

Antenatal dietary advice and supplementation to increase energy and protein intake

BACKGROUND

Gestational weight gain is positively associated with fetal growth, and observational studies of food supplementation in pregnancy have reported increases in gestational weight gain and fetal growth.

OBJECTIVES

To assess the effects of advice during pregnancy to increase energy and protein intake, or of actual energy and protein supplementation, on energy and protein intakes, and the effect on maternal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (22 July 2011) and contacted researchers in the field. We updated the search on 12 July 2012 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

Randomised controlled trials of dietary advice to increase energy and protein intake, or of actual energy and protein supplementation, during pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and checked for accuracy. Extracted data were supplemented by additional information from the trialists we contacted.

MAIN RESULTS

We examined 110 reports corresponding to 46 trials. Of these trials, 15 were included, 30 were excluded, and one is ongoing. Overall, 15 trials involving 7410 women were included.Nutritional advice (four trials, 790 women)Women given nutritional advice had a lower relative risk of having a preterm birth (two trials, 449 women) (risk ratio (RR) 0.46, 95% CI 0.21 to 0.98 ), head circumference at birth was increased in one trial (389 women) (mean difference (MD) 0.99 cm, 95% CI 0.43 to 1.55) and protein intake increased (three trials, 632 women) (protein intake: MD +6.99 g/day, 95% CI 3.02 to 10.97). No significant differences were observed on any other outcomes.Balanced energy and protein supplementation (11 trials, 5385 women)Risk of stillbirth was significantly reduced for women given balanced energy and protein supplementation (RR 0.62, 95% CI 0.40 to 0.98, five trials, 3408 women), mean birthweight was significantly increased (random-effects MD +40.96 g, 95% CI 4.66 to 77.26 , Tau(2)= 1744, I(2) = 44%, 11 trials, 5385 women). There was also a significant reduction in the risk of small-for-gestational age (RR 0.79, 95% CI 0.69 to 0.90, I(2) = 16%, seven trials, 4408 women). No significant effect was detected for preterm birth or neonatal death.High-protein supplementation (one trial, 1051 women)High-protein supplementation (one trial, 505 women), was associated with a significantly increased risk of small-for-gestational age babies (RR 1.58, 95% CI 1.03 to 2.41).Isocaloric protein supplementation (two trials, 184 women)Isocaloric protein supplementation (two trials,184 women) had no significant effect on birthweight and weekly gestational weight gain.

AUTHORS' CONCLUSIONS

This review provides encouraging evidence that antenatal nutritional advice with the aim of increasing energy and protein intake in the general obstetric population appears to be effective in reducing the risk of preterm birth, increasing head circumference at birth and increasing protein intake, there was no evidence of benefit or adverse effect for any other outcome reported.Balanced energy and protein supplementation seems to improve fetal growth, and may reduce the risk of stillbirth and infants born small-for-gestational age. High-protein supplementation does not seem to be beneficial and may be harmful to the fetus. Balanced-protein supplementation alone had no significant effects on perinatal outcomes.The results of this review should be interpreted with caution, the risk of bias was either unclear or high for at least one category examined in several of the included trials and the quality of the evidence was low for several important outcomes. Also the anthropometric characteristics of the general obstetric population is changing, therefore, those developing interventions aimed at altering energy and protein intake should ensure that only those women likely to benefit are included. Large, well designed randomised trials are needed to assess the effects of increasing energy and protein intake during pregnancy in women whose intake is below recommended levels.

The human milk microbiome changes over lactation and is shaped by maternal weight and mode of delivery

BACKGROUND

Breast milk is recognized as the most important postpartum element in metabolic and immunologic programming of health of neonates. The factors influencing the milk microbiome and the potential impact of microbes on infant health have not yet been uncovered.

OBJECTIVE

Our objective was to identify pre- and postnatal factors that can potentially influence the bacterial communities inhabiting human milk.

DESIGN

We characterized the milk microbial community at 3 different time points by pyrosequencing and quantitative polymerase chain reaction in mothers (n = 18) who varied in BMI, weight gain, and mode of delivery.

RESULTS

We found that the human milk microbiome changes over lactation. Weisella, Leuconostoc, Staphylococcus, Streptococcus, and Lactococcus were predominant in colostrum samples, whereas in 1- and 6-mo milk samples the typical inhabitants of the oral cavity (eg, Veillonella, Leptotrichia, and Prevotella) increased significantly. Milk from obese mothers tended to contain a different and less diverse bacterial community compared with milk from normal-weight mothers. Milk samples from elective but not from nonelective mothers who underwent cesarean delivery contained a different bacterial community than did milk samples from individuals giving birth by vaginal delivery, suggesting that it is not the operation per se but rather the absence of physiological stress or hormonal signals that could influence the microbial transmission process to milk.

CONCLUSIONS

Our results indicate that milk bacteria are not contaminants and suggest that the milk microbiome is influenced by several factors that significantly skew its composition. Because bacteria present in breast milk are among the very first microbes entering the human body, our data emphasize the necessity to understand the biological role that the milk microbiome could potentially play for human health.

Host remodeling of the gut microbiome and metabolic changes during pregnancy

Many of the immune and metabolic changes occurring during normal pregnancy also describe metabolic syndrome. Gut microbiota can cause symptoms of metabolic syndrome in nonpregnant hosts. Here, to explore their role in pregnancy, we characterized fecal bacteria of 91 pregnant women of varying prepregnancy BMIs and gestational diabetes status and their infants. Similarities between infant-mother microbiotas increased with children's age, and the infant microbiota was unaffected by mother's health status. Gut microbiota changed dramatically from first (T1) to third (T3) trimesters, with vast expansion of diversity between mothers, an overall increase in Proteobacteria and Actinobacteria, and reduced richness. T3 stool showed strongest signs of inflammation and energy loss; however, microbiome gene repertoires were constant between trimesters. When transferred to germ-free mice, T3 microbiota induced greater adiposity and insulin insensitivity compared to T1. Our findings indicate that host-microbial interactions that impact host metabolism can occur and may be beneficial in pregnancy.

Maternal weight and excessive weight gain during pregnancy modify the immunomodulatory potential of breast milk

INTRODUCTION

Breast milk is an optimal source of nutrition for infants. It contains bioactive components including bacteria that support the microbial colonization and immune system development of the infant. The determinants of human milk composition remain poorly understood, although maternal nutritional and immunological status as well as lifestyle and dietary habits seem to have an impact.

METHODS

The subjects selected were women from a prospective follow-up study categorized by BMI. Milk samples were taken after delivery and at 1 and 6 mo later for analysis of composition in regard to transforming growth factor (TGF)-β2, soluble CD14 (sCD14), cytokines, and microbiota.

RESULTS

TGF-β2 and sCD14 levels in the breast milk of overweight mothers tended to be lower than the levels in that of normal-weight mothers. Also, higher levels of Staphylococcus group bacteria and lower levels of Bifidobacterium group bacteria were detected in overweight mothers as compared with normal-weight ones. The prevalence of Akkermansia muciniphila-type bacteria was also higher in overweight mothers, and the numbers of these bacteria were related to the interleukin (IL)-6 concentration in the colostrum, which was in turn related to lower counts of Bifidobacterium group bacteria in the breast milk of overweight women.

DISCUSSION

Complex interactions of cytokines and microbiota in breast milk guide the microbiological, immunological, and metabolic programming of infant health. Our data may indicate the presence of an additional mechanism that may explain the heightened risk of obesity for infants of overweight and excessive weight gain mothers.

Microbial ecology and host-microbiota interactions during early life stages

The role of human microbiota has been redefined during recent years and its physiological role is now much more important than earlier understood. Intestinal microbial colonization is essential for the maturation of immune system and for the developmental regulation of the intestinal physiology. Alterations in this process of colonization have been shown to predispose and increase the risk to disease later in life. The first contact of neonates with microbes is provided by the maternal microbiota. Moreover, mode of delivery, type of infant feeding and other perinatal factors can influence the establishment of the infant microbiota. Taken into consideration all the available information it could be concluded that the exposure to the adequate microbes early in gestation and neonatal period seems to have a relevant role in health. Maternal microbial environment affects maternal and fetal immune physiology and, of relevance, this interaction with microbes at the fetal-maternal interface could be modulated by specific microbes administered to the pregnant mother. Indeed, probiotic interventions aiming to reduce the risk of immune-mediated diseases may appear effective during early life.

Nutrition education and counselling provided during pregnancy: effects on maternal, neonatal and child health outcomes

Nutrition education and counselling (NEC) is a commonly applied strategy to improve maternal nutrition during pregnancy. However, with the exception special populations and specific diets, the effect of NEC on maternal, neonatal and child health outcomes has not been systematically reviewed. Using a modified Child Health Epidemiology Reference Group method we systematically reviewed the literature and identified and abstracted 37 articles. We conducted meta-analyses for the effect of NEC on maternal, neonatal and infant health outcomes including gestational weight gain, maternal anaemia, birthweight, low birthweight and preterm delivery. NEC significantly improved gestational weight gain by 0.45 kg, reduced the risk of anaemia in late pregnancy by 30%, increased birthweight by 105 g and lowered the risk of preterm delivery by 19%. The effect of NEC on risk of low birthweight was not significant. The effect of NEC was greater when provided with nutrition support, for example, food or micronutrient supplements or nutrition safety nets. The overall quality of the body of evidence was deemed low for all outcomes due to high heterogeneity, poor study designs and other biases. Additional well-designed research that is grounded in appropriate theories of behaviour change is needed to improve confidence in the effect of NEC. Further, cost-effectiveness research is needed to clarify the added benefit and sustainability of providing NEC with nutritional support and/or safety nets, especially in areas where food insecurity and gender bias may limit women's capacity to adhere to NEC messages.

Development of healthy gut microbiota early in life

A healthy intestinal microbiota profile in early life is related to health later in life. An aberrant composition is associated with risks of systemic problems, such as obesity, diabetes and allergic diseases, including asthma and enteric inflammatory conditions, sometimes manifesting at 7 years of age. A healthy and balanced gut microbiota profile in infancy, especially with regard to bifidobacteria, is directly related to mode of delivery (natural birth) and quality of breast milk, which in turn is affected by the mother's own systemic health and nutritional status. Pregnant women of normal body weight and healthy microbiota profiles, both gut microbiota and breast milk microbiota, have greater opportunities to pass on compounds, antigens modified by the mother's gut and other agents that promote the development of a healthy immune system in the breastfed infant.