Maternal consumption of artificially sweetened beverages during pregnancy is associated with infant gut microbiota and metabolic modifications and increased infant body mass index

Effect of perinatal consumption of low-calorie sweetener on maternal health: A systematic review and meta-analysis

BACKGROUND AND AIMS

Evidence regarding perinatal low-calorie (or artificial) sweetener (LCS) consumption and its effect on maternal health outcomes is limited and inconclusive. The primary outcomes of our systematic review and meta-analysis were the effect of preconception and pregnancy LCS exposure on reproductive and pregnancy outcomes. Secondary outcomes included long-term maternal health.

METHODS

A systematic search of electronic databases, including PubMed, Embase, CINAHL, the Cochrane Library, Scopus, Web of Science, PsycINFO, ProQuest Health and Medical, ClinicalTrials.gov and Google Scholar, was conducted up to 20 November 2023. Primary studies, including clinical trials, cohort studies, case-control studies, which reported any LCS consumption during perinatal period and pregnancy and maternal health outcomes were eligible. A random effects model with restricted maximum likelihood estimation was used for the meta-analysis. We appraised the quality of the included studies using the National Institute of Health study quality appraisal tool and the overall quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation tool.

RESULTS

A total of 19 eligible studies with 203,706 participants were included. LCS consumption during pregnancy was associated with 11% increased risk of preterm birth (RR = 1.11, 95% CI: 1.07-1.16, I2 = 0.01%) and 42% increased risk of gestational diabetes (RR = 1.42, 95% CI: 0.98-2.04, I2 = 67.60%) compared with no consumption, however, the effect size for gestational diabetes was not precise as the 95% CI indicated that the effect estimate could range from 2% lower risk to 204% (or 2.04 times) higher risk. We found no association between LCS consumption during pregnancy and gestational weight gain (standardized mean difference (SMD) = 0.04; 95% CI: -0.17 - 0.24, I2 = 41.31%) or gestational age at birth (SMD = 0.00; 95% CI: -0.13 - 0.14, I2 = 80.13%). The effect of LCS consumption on reproductive treatment outcomes were inconsistent.

CONCLUSIONS

Based on the evidence available, LCS consumption in pregnancy was associated with increased risk of preterm birth and gestational diabetes. Robust research, such as well-designed randomized trials and large prospective cohort studies, is required to confirm the causal effect of LCS consumption during perinatal period on adverse maternal health outcomes.

Association between low-calorie sweetener consumption during pregnancy and child health: A systematic review and meta-analysis

We examined the association between low-calorie sweeteners (LCS) consumption during preconception, pregnancy, and breastfeeding and child health outcomes. A systematic search of electronic databases in PubMed, Embase, Cumulated Index to Nursing and Allied Health Literature, the Cochrane Library, Scopus, Web of Science, PsycINFO, ProQuest Health and Medical, ClinicalTrials.gov, and Google Scholar was conducted up to 21 September 2023. A random effects model with restricted maximum likelihood estimation was used for the meta-analysis. Seventeen eligible studies were included. The standardised mean difference (SMD) and 95% confidence interval (CI) in birth weight between those who frequently consumed LCS (≥1 serve/day) during pregnancy and those who did not consume LCS was 0.04 (0.00, 0.08) (four cohort studies). Any LCS consumption during pregnancy compared with no consumption was not associated with birth weight [SMD (95% CI) = 0.03 (-0.03, 0.08)] (four cohort studies). Any LCS consumption during pregnancy was not associated with body mass index z-scores. The weighted mean difference (95% CI) was 0.00 (-0.05, 0.06) at birth, 0.06 (-0.29, 0.40) at 6 months, -0.04 (-0.19, 0.10) at 1 year, 0.00 (-0.16, 0.17) at 3 years, and 0.10 (-0.15, 0.34) at 7 years of the child age, compared with no intake (five cohort studies). The odds of being overweight at 1 year among children exposed to LCS during pregnancy was 1.19 (OR [95% CI]: 1.19 [0.81, 1.58]) compared with unexposed children (two cohort studies). The effect sizes were not precise for all the outcomes as the 95% CI indicated the effect estimates could range from small protective to a higher risk. The effect of LCS consumption on child behaviour and cognition was inconsistent. There is not enough evidence to confirm LCS consumption during pregnancy affects birth weight and risk of overweight in children. However, frequent consumption increased birth weight and the risk of overweight at different ages, though the effects were imprecise. More robust research evidence is required as the quality of evidence is low.

Early-Life Gut Microbiota: A Possible Link Between Maternal Exposure to Non-Nutritive Sweeteners and Metabolic Syndrome in Offspring

Metabolic syndrome (MetS) is recognized as a group of metabolic abnormalities, characterized by clustered interconnected traits that elevate the risks of obesity, cardiovascular and atherosclerotic diseases, hyperlipidemia, and type 2 diabetes mellitus. Non-nutritive sweeteners (NNS) are commonly consumed by those with imbalanced calorie intake, especially in the perinatal period. In the past, accumulating evidence showed the transgenerational and mediated roles of human microbiota in the development of early-life MetS. Maternal exposure to NNS has been recognized as a risk factor for filial metabolic disturbance through various mechanisms, among which gut microbiota and derived metabolites function as nodes linking NNS and MetS in early life. Despite the widespread consumption of NNS, there remain growing concerns about their transgenerational impact on metabolic health. There is growing evidence of NNS being implicated in the development of metabolic abnormalities. Intricate complexities exist and a comprehensive understanding of how the gut microbiota interacts with mechanisms related to maternal NNS intake and disrupts metabolic homeostasis of offspring is critical to realize its full potential in preventing early-life MetS. This review aims to elucidate the effects of early-life gut microbiota and links to maternal NNS exposure and imbalanced offspring metabolic homeostasis and discusses potential perspectives and challenges, which may provide enlightenment and understanding into optimal perinatal nutritional management.

Ultra-processed foods, allergy outcomes and underlying mechanisms in children: An EAACI task force report

BACKGROUND

Consumption of ultra-processed foods [UPFs] may be associated with negative health outcomes. Limited data exist regarding the potential role of UPFs in the occurrence of allergic diseases. The underlying mechanisms underpinning any such associations are also poorly elucidated.

METHODS

We performed a systematic review and narrative evidence synthesis of the available literature to assess associations between UPF consumption and pediatric allergy outcomes (n = 26 papers), including data on the association seen with the gut microbiome (n = 16 papers) or immune system (n = 3 papers) structure and function following PRISMA guidelines.

RESULTS

Dietary exposure to fructose, carbonated soft drinks, and sugar intake was associated with an increased risk of asthma, allergic rhinitis, and food allergies in children. Commercial baby food intake was associated with childhood food allergy. Childhood intake of fructose, fruit juices, sugar-sweetened beverages, high carbohydrate UPFs, monosodium glutamate, UPFs, and advanced glycated end-products (AGEs) was associated with the occurrence of allergic diseases. Exposure to UPFs and common ingredients in UPFs seem to be associated with increased occurrence of allergic diseases such as asthma, wheezing, food allergies, atopic dermatitis, and allergic rhinitis, in many, but not all studies.

CONCLUSION

More preclinical and clinical studies are required to better define the link between UPF consumption and the risk of allergies and asthma. These observational studies ideally require supporting data with clearly defined UPF consumption, validated dietary measures, and mechanistic assessments to definitively link UPFs with the risk of allergies and asthma.

Artificial sweeteners and risk of incident cardiovascular disease and mortality: evidence from UK Biobank

BACKGROUND

Artificial sweeteners are widely popular worldwide as substitutes for sugar or caloric sweeteners, but there are still several important unknowns and controversies regarding their associations with cardiovascular disease (CVD). We aimed to extensively assess the association and subgroup variability between artificial sweeteners and CVD and CVD mortality in the UK Biobank cohort, and further investigate the modification effects of genetic susceptibility and the mediation role of type 2 diabetes mellitus (T2DM).

METHODS

This study included 133,285 participants in the UK Biobank who were free of CVD and diabetes at recruitment. Artificial sweetener intake was obtained from repeated 24-hour diet recalls. Cox proportional hazard models were used to estimate HRs. Genetic predisposition was estimated using the polygenic risk score (PRS). Furthermore, time-dependent mediation was performed.

RESULTS

In our study, artificial sweetener intake (each teaspoon increase) was significantly associated with an increased risk of incident overall CVD (HR1.012, 95%CI: 1.008,1.017), coronary artery disease (CAD) (HR: 1.018, 95%CI: 1.001,1.035), peripheral arterial disease (PAD) (HR: 1.035, 95%CI: 1.010,1.061), and marginally significantly associated with heart failure (HF) risk (HR: 1.018, 95%CI: 0.999,1.038). In stratified analyses, non-whites were at greater risk of incident overall CVD from artificial sweetener. People with no obesity (BMI < 30 kg/m2) also tended to be at greater risk of incident CVD from artificial sweetener, although the obesity interaction is not significant. Meanwhile, the CVD risk associated with artificial sweeteners is independent of genetic susceptibility, and no significant interaction exists between genetic susceptibility and artificial sweeteners in terms of either additive or multiplicative effects. Furthermore, our study revealed that the relationship between artificial sweetener intake and overall CVD is significantly mediated, in large part, by prior T2DM (proportion of indirect effect: 70.0%). In specific CVD subtypes (CAD, PAD, and HF), the proportion of indirect effects ranges from 68.2 to 79.9%.

CONCLUSIONS

Our findings suggest significant or marginally significant associations between artificial sweeteners and CVD and its subtypes (CAD, PAD, and HF). The associations are independent of genetic predisposition and are mediated primarily by T2DM. Therefore, the large-scale application of artificial sweeteners should be prudent, and the responses of individuals with different characteristics to artificial sweeteners should be better characterized to guide consumers' artificial sweeteners consumption behavior.

Polygenic Risk Scores and the Risk of Childhood Overweight/Obesity in Association With the Consumption of Sweetened Beverages: A Population-Based Cohort Study

Background: Sugar-sweetened beverage (SSB) and non-nutritive sweetened beverage (NNSB) consumption is associated with obesity and are targets for population-level dietary interventions. In children (<16 years), we evaluate whether SSB or NNSB consumption is associated with subsequent (2 years later) overweight and/or obesity, and the effect of consumption on subsequent overweight/obesity differs by BMI polygenic risk score (BMI-PRS). Methods: The nationally representative Longitudinal-Study-of-Australian-Children had biennial data collection from birth (n = 5107) until age 14/15 years (n = 3127). At age 11/12 years, a comprehensive biomedical assessment, including PRS assessment, was undertaken (n = 1422). Parent- or self-reported beverage consumption (SSBs: soft drinks, energy drinks, and/or juice; NNSBs: diet drinks) was measured as any/none over previous 24 hours. BMI-PRS was derived using published results (high PRS ≥75th percentile). At ages 4/5-14/15 children were classified as having obesity, overweight/obesity, or not having overweight/obesity using BMI z-score (CDC cut points). Results: SSB consumption had limited association with subsequent overweight/obesity. NNSB consumption was associated with ∼8% more children with subsequent overweight/obesity at most ages. In older children with high BMI-PRS, associations between NNSB consumption and subsequent overweight/obesity strengthened with age [at age 14-15 for high BMI-PRS, difference in proportion with overweight/obesity among NNSB consumers vs. nonconsumers = 0.38 (95% confidence interval: 0.22 to 0.55, p ≤ 0.001)]. There was limited association between SSB consumption and BMI-PRS. Conclusion: NNSB consumption was associated with increased risk of overweight/obesity for children with greater genetic risk at older ages (12-15 years). Focused intervention among children with high genetic risk could target NNSB consumption; however, reverse causality (children with genetic risk and/or high BMI consume more NNSBs) cannot be excluded.

Obesogenic potentials of environmental artificial sweeteners with disturbances on both lipid metabolism and neural responses

Artificial sweeteners (ASs) entered the environments after application and emissions. Recent studies showed that some ASs had obesogenic risks. However, it remained unclear whether such risks are common and how they provoke such effects. Presently, the effects of 8 widely used ASs on lipid accumulation were measured in Caenorhabditis elegans. Potential mechanisms were explored with feeding and locomotion behavior, lipid metabolism and neural regulation. Results showed that acesulfame (ACE), aspartame (ASP), saccharin sodium (SOD), sucralose (SUC) and cyclamate (CYC) stimulated lipid accumulation at μg/L levels, showing obesogenic potentials. Behavior investigation showed that ACE, ASP, SOD, SUC and CYC biased more feeding in the energy intake aspect against the locomotion in the energy consumption one. Neotame (NEO), saccharin (SAC) and alitame (ALT) reduced the lipid accumulation without significant obesogenic potentials in the present study. However, all 8 ASs commonly disturbed enzymes (e.g., acetyl-CoA carboxylase) in lipogenesis and those (e.g., carnitine palmitoyl transferase) in lipolysis. In addition, ASs disturbed PPARγ (via expressions of nhr-49), TGF-β/DAF-7 (daf-7) and SREBP (sbp-1) pathways. Moreover, they also interfered neurotransmitters including serotonin (5-HT), dopamine (DA) and acetylcholine (ACh), with influences in Gsα (e.g., via expressions of gsα-1, ser-7), glutamate (e.g., mgl-1), and cGMP-dependent signaling pathways (e.g., egl-4). In summary, environmental ASs commonly disturbed neural regulation connecting behavior and lipid metabolism, and 5 out of 8 showed clear obesogenic potentials. ENVIRONMENTAL IMPLICATION: Artificial sweeteners (ASs) are become emerging pollutants after wide application and continuous emission. Recent studies showed that some environmental ASs had obesogenic risks. The present study employed Caenorhabditis elegans to explore the influences of 8 commonly used ASs on lipid metabolisms and also the underlying mechanisms. Five out of 8 ASs stimulated lipid accumulation at μg/L levels, and they biased energy intake against energy consumption. The other three ASs reduced the lipid accumulation. ASs commonly disturbed lipogenesis and lipolysis via PPARγ, TGF-β and SREBP pathways, and also influenced neurotransmitters with Gsα, glutamate and cGMP-dependent signaling pathways.

The impact of non-nutritive sweeteners on fertility, maternal and child health outcomes: a review of human and animal studies

There is significant evidence that an unhealthy diet greatly increases the risk of complications during pregnancy and predisposes offspring to metabolic dysfunction and obesity. While fat intake is typically associated with the onset of obesity and its comorbidities, there is increasing evidence linking sugar, particularly high fructose corn syrup, to the global rise in obesity rates. Furthermore, the detrimental effects of added sugar intake during pregnancy on mother and child have been clearly outlined. Guidelines advising pregnant women to avoid food and beverages with high fat and sugar have led to an increase in consumption of 'diet' or 'light' options. Examination of some human birth cohort studies shows that heavy consumption (at least one beverage a day) of non-nutritive sweetener (NNS) containing beverages has been associated with increased risk of preterm birth and increased weight/BMI in male offspring independent of maternal weight, which appears to be offset by breastfeeding for 6 months. Rodent models have shown that NNS exposure during pregnancy can impact maternal metabolic health, adipose tissue function, gut microbiome profiles and taste preference. However, the mechanisms underlying these effects are multifaceted and further research, particularly in a translational setting is required to fully understand the effects of NNS on maternal and infant health during pregnancy. Therefore, this review examines maternal sweetener intakes and their influence on fertility, maternal health outcomes and offspring outcomes in human cohort studies and rodent models.

Reply to Ayoub-Charette et al. Lack of Biological Plausibility and Major Methodological Issues Cast Doubt on the Association between Aspartame and Autism. Comment on "Fowler et al. Daily Early-Life Exposures to Diet Soda and Aspartame Are Associated with Autism in Males: A Case-Control Study. Nutrients 2023, 15, 3772"

Thank you for the opportunity to respond to the concerns raised by Ayoub-Charette et al [...].

Divergent maturational patterns of the infant bacterial and fungal gut microbiome in the first year of life are associated with inter-kingdom community dynamics and infant nutrition

BACKGROUND

The gut microbiome undergoes primary ecological succession over the course of early life before achieving ecosystem stability around 3 years of age. These maturational patterns have been well-characterized for bacteria, but limited descriptions exist for other microbiota members, such as fungi. Further, our current understanding of the prevalence of different patterns of bacterial and fungal microbiome maturation and how inter-kingdom dynamics influence early-life microbiome establishment is limited.

RESULTS

We examined individual shifts in bacterial and fungal alpha diversity from 3 to 12 months of age in 100 infants from the CHILD Cohort Study. We identified divergent patterns of gut bacterial or fungal microbiome maturation in over 40% of infants, which were characterized by differences in community composition, inter-kingdom dynamics, and microbe-derived metabolites in urine, suggestive of alterations in the timing of ecosystem transitions. Known microbiome-modifying factors, such as formula feeding and delivery by C-section, were associated with atypical bacterial, but not fungal, microbiome maturation patterns. Instead, fungal microbiome maturation was influenced by prenatal exposure to artificially sweetened beverages and the bacterial microbiome, emphasizing the importance of inter-kingdom dynamics in early-life colonization patterns.

CONCLUSIONS

These findings highlight the ecological and environmental factors underlying atypical patterns of microbiome maturation in infants, and the need to incorporate multi-kingdom and individual-level perspectives in microbiome research to improve our understandings of gut microbiome maturation patterns in early life and how they relate to host health. Video Abstract.

Effect of low-and non-calorie sweeteners on the gut microbiota: A review of clinical trials and cross-sectional studies

Use of non-nutritive sweeteners (NNSs) has increased worldwide in recent decades. However, evidence from preclinical studies shows that sweetener consumption may induce glucose intolerance through changes in the gut microbiota, which raises public health concerns. As studies conducted on humans are lacking, the aim of this review was to gather and summarize the current evidence on the effects of NNSs on human gut microbiota. Only clinical trials and cross-sectional studies were included in the review. Regarding NNSs (i.e, saccharin, sucralose, aspartame, and stevia), only two of five clinical trials showed significant changes in gut microbiota composition after the intervention protocol. These studies concluded that saccharin and sucralose impair glycemic tolerance. In three of the four cross-sectional studies an association between NNSs and the microbial composition was observed. All three clinical trials on polyols (i.e, xylitol) showed prebiotic effects on gut microbiota, but these studies had multiple limitations (publication date, dosage, duration) that jeopardize their validity. The microbial response to NNSs consumption could be strongly mediated by the gut microbial composition at baseline. Further studies in which the potential personalized microbial response to NNSs consumption is acknowledged, and that include longer intervention protocols, larger cohorts, and more realistic sweetener dosage are needed to broaden these findings.

Evidence of the Involvement of Nematostoma parasiticum in Herpotrichia Needle Browning of Abies balsamea

Herpotrichia needle browning (HNB) is a disease that affects several species of fir trees in Europe and North America. HNB was first described by Hartig in 1884, who isolated a fungal pathogenic agent identified as responsible for the disease. This fungus was later named Herpotrichia parasitica but is currently named Nematostoma parasiticum. However, the identity of the pathogens causing HNB is regularly questioned and, to date, the true causal agent of this disease has not been definitely established. The present study aimed to identify the fungal populations present in needles of Christmas fir trees (Abies balsamea) and to correlate them with needle health status using robust molecular methods. PCR primers specific to N. parasiticum allowed detection of the presence of this fungus in DNA samples from symptomatic needles. Furthermore, high-throughput sequencing (Illumina MiSeq) clearly showed that N. parasiticum was associated with symptomatic needles. However, high-throughput sequencing results revealed that the presence of other species such as Sydowia polyspora and Rhizoctonia sp. may also correlate with the development of HNB. A diagnostic tool, based on quantitative PCR using a probe, was then developed to detect and quantify N. parasiticum in DNA samples. The efficacy of this molecular approach was validated through the detection of the pathogenic agent in symptomatic needle samples as well as in nonsymptomatic needles collected in trees affected by HNB. In contrast, N. parasiticum could not be found in needles from healthy trees. The present study argues for the importance of N. parasiticum in causing HNB symptoms.

Infant gut microbiota colonization: influence of prenatal and postnatal factors, focusing on diet

Maternal microbiota forms the first infant gut microbial inoculum, and perinatal factors (diet and use of antibiotics during pregnancy) and/or neonatal factors, like intra partum antibiotics, gestational age and mode of delivery, may influence microbial colonization. After birth, when the principal colonization occurs, the microbial diversity increases and converges toward a stable adult-like microbiota by the end of the first 3-5 years of life. However, during the early life, gut microbiota can be disrupted by other postnatal factors like mode of infant feeding, antibiotic usage, and various environmental factors generating a state of dysbiosis. Gut dysbiosis have been reported to increase the risk of necrotizing enterocolitis and some chronic diseases later in life, such as obesity, diabetes, cancer, allergies, and asthma. Therefore, understanding the impact of a correct maternal-to-infant microbial transfer and a good infant early colonization and maturation throughout life would reduce the risk of disease in early and late life. This paper reviews the published evidence on early-life gut microbiota development, as well as the different factors influencing its evolution before, at, and after birth, focusing on diet and nutrition during pregnancy and in the first months of life.

Artificial sweeteners and cardiovascular risk

PURPOSE OF REVIEW

Globalization and the increase in consumption of ultra-processed foods have led to a need for greater knowledge on the health impacts of certain nutrients such as artificial sweeteners. This review aims to analyse the role of artificial sweeteners (nutritive and nonnutritive) and their impact on cardiometabolic and cardiovascular disease (CVD) risk.

RECENT FINDINGS

The detrimental effects of a high-calorie, high-sugar diet have been well established. In light of this, health authorities recommend limiting sugar consumption. This has led the food industry to develop different artificial sweeteners with specific properties, such as flavour and stability (nutritive artificial sweeteners: NAS), and others aimed at limiting sugar in the diet (nonnutritive artificial sweeteners: nNAS). Likewise, recent evidence explores the influence of artificial sweeteners (NAS and nNAS) on CVD risk through risk factors such as obesity and type 2 diabetes mellitus, among others.

SUMMARY

This review aims to provide an updated overview of the impact of NAS and nNAS on cardiovascular health and provide recommendations regarding their consumption.

Associations between sugar-sweetened beverages before and during pregnancy and offspring overweight/obesity in Japanese women: the TMM BirThree Cohort Study

OBJECTIVE

The association between high sugar-sweetened beverages (SSB) intake during pregnancy and offspring overweight/obesity has been reported only from Western countries. The objective of this study was to examine the association between SSB intake before and during pregnancy and offspring overweight/obesity among Japanese women.

DESIGN

Japanese prospective birth cohort study.

SETTING

We analysed mother-offspring pairs who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study from 2013 to 2017. SSB intake during pregnancy was evaluated using the FFQ and classified into three groups: none (0 g/d), medium (<195 g/d) and high (>195 g/d). Overweight or obesity at 1 year of age in offspring was defined as having a BMI Z-score greater than 2 sd, calculated based on the BMI reference data for Japanese children. Multiple logistic regression analyses were performed to examine the associations between SSB intake before and during pregnancy and offspring overweight/obesity, after adjusting for covariates.

PARTICIPANTS

Japanese mother-offspring pairs (n 7114).

RESULTS

The overweight/obesity rate of the offspring was 8·8 %. Pregnant women with a high intake of SSB in early to mid-pregnancy had a higher risk of overweight/obesity in their offspring compared with those who did not; the OR was 1·52 (95 % CI (1·09, 2·12)).

CONCLUSIONS

High SSB intake in early to mid-pregnancy was associated with an increased risk of offspring overweight/obesity at 1 year of age.

Maternal low-calorie sweetener consumption rewires hypothalamic melanocortin circuits via a gut microbial co-metabolite pathway

The prevalence of obesity and type 2 diabetes is growing at an alarming rate, including among pregnant women. Low-calorie sweeteners (LCSs) have increasingly been used as an alternative to sugar to deliver a sweet taste without the excessive caloric load. However, there is little evidence regarding their biological effects, particularly during development. Here, we used a mouse model of maternal LCS consumption to explore the impact of perinatal LCS exposure on the development of neural systems involved in metabolic regulation. We report that adult male, but not female, offspring from both aspartame- and rebaudioside A-exposed dams displayed increased adiposity and developed glucose intolerance. Moreover, maternal LCS consumption reorganized hypothalamic melanocortin circuits and disrupted parasympathetic innervation of pancreatic islets in male offspring. We then identified phenylacetylglycine (PAG) as a unique metabolite that was upregulated in the milk of LCS-fed dams and the serum of their pups. Furthermore, maternal PAG treatment recapitulated some of the key metabolic and neurodevelopmental abnormalities associated with maternal LCS consumption. Together, our data indicate that maternal LCS consumption has enduring consequences on the offspring's metabolism and neural development and that these effects are likely to be mediated through the gut microbial co-metabolite PAG.

Effect of Maternal Diet on Maternal Milk and Breastfed Infant Gut Microbiomes: A Scoping Review

While it is widely recognized that nutrition during pregnancy and lactation can affect the microbiome of breast milk as well as the formation of the infant gut microbiome, we are only just beginning to understand the extent to which maternal diet impacts these microbiomes. Given the importance of the microbiome for infant health, we conducted a comprehensive review of the published literature to explore the current scope of knowledge regarding associations between maternal diet and the breast milk and infant gut microbiomes. Papers included in this review assessed either diet during lactation or pregnancy, and the milk and/or infant gut microbiome. Sources included cohort studies, randomized clinical trials, one case-control study, and one crossover study. From an initial review of 808 abstracts, we identified 19 reports for a full analysis. Only two studies assessed the effects of maternal diet on both milk and infant microbiomes. Although the reviewed literature supports the importance of a varied, nutrient-dense maternal diet in the formation of the infant’s gut microbiome, several studies found factors other than maternal diet to have a greater impact on the infant microbiome.

Maturational patterns of the infant gut mycobiome are associated with early-life body mass index

Unlike the bacterial microbiome, the role of early-life gut fungi in host metabolism and childhood obesity development remains poorly characterized. To address this, we investigate the relationship between the gut mycobiome of 100 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study and body mass index Z scores (BMIz) in the first 5 years of life. An increase in fungal richness during the first year of life is linked to parental and infant BMI. The relationship between richness pattern and early-life BMIz is modified by maternal BMI, maternal diet, infant antibiotic exposure, and bacterial beta diversity. Further, the abundances of Saccharomyces, Rhodotorula, and Malassezia are differentially associated with early-life BMIz. Using structural equation modeling, we determine that the mycobiome's contribution to BMIz is likely mediated by the bacterial microbiome. This demonstrates that mycobiome maturation and infant growth trajectories are distinctly linked, advocating for inclusion of fungi in larger pediatric microbiome studies.

Habitual intakes of sugar-sweetened beverages associated with gut microbiota-related metabolites and metabolic health outcomes in young Chinese adults

BACKGROUND AND AIMS

Reducing consumption of sugar-sweetened beverages (SSBs) is a global public health priority because of their limited nutritional value and associations with increased risk of obesity and metabolic diseases. Gut microbiota-related metabolites emerged as quintessential effectors that may mediate impacts of dietary exposures on the modulation of host commensal microbiome and physiological status.

METHODS AND RESULTS

This study assessed the associations among SSBs, circulating microbial metabolites, and gut microbiota-host co-metabolites, as well as metabolic health outcomes in young Chinese adults (n = 86), from the Carbohydrate Alternatives and Metabolic Phenotypes study in Shaanxi Province. Five principal component analysis-derived beverage drinking patterns were determined on self-reported SSB intakes, which were to a varying degree associated with 143 plasma levels of gut microbiota-related metabolites profiled by untargeted metabolomics. Moreover, carbonated beverages, fruit juice, energy drinks, and bubble tea exhibited positive associations with obesity-related markers and blood lipids, which were further validated in an independent cohort of 16,851 participants from the Regional Ethnic Cohort Study in Northwest China in Shaanxi Province. In contrast, presweetened coffee was negatively associated with the obesity-related traits. A total of 79 metabolites were associated with both SSBs and metabolic markers, particularly obesity markers. Pathway enrichment analysis identified the branched-chain amino acid catabolism and aminoacyl-tRNA biosynthesis as linking SSB intake with metabolic health outcomes.

CONCLUSION

Our findings demonstrate the associations between habitual intakes of SSBs and several metabolic markers relevant to noncommunicable diseases, and highlight the critical involvement of gut microbiota-related metabolites in mediating such associations.

Insulin resistance in Alzheimer's disease: The genetics and metabolomics links

Alzheimer's disease (AD) is a neurodegenerative disease with significant socioeconomic burden worldwide. Although genetics and environmental factors play a role, AD is highly associated with insulin resistance (IR) disorders such as metabolic syndrome (MS), obesity, and type two diabetes mellitus (T2DM). These findings highlight a shared pathogenesis. The use of metabolomics as a downstream systems' biology (omics) approach can help to identify these shared metabolic traits and assist in the early identification of at-risk groups and potentially guide therapy. Targeting the shared AD-IR metabolic trait with lifestyle interventions and pharmacological treatments may offer promising AD therapeutic approach. In this narrative review, we reviewed the literature on the AD-IR pathogenic link, the shared genetics and metabolomics biomarkers between AD and IR disorders, as well as the lifestyle interventions and pharmacological treatments which target this pathogenic link.

Maternal-Child Microbiome and Impact on Growth and Neurodevelopment in Infants and Children: A Scoping Review

BACKGROUND

Pathologic changes in the microbiome (dysbiosis) have been implicated in affecting the growth and neurodevelopment of infants and children. There is evidence to suggest that prenatal and postnatal stressors may be a factor in dysbiosis and there is also a growing body of evidence to suggest that interventions may reduce this negative impact. A scoping review was undertaken to identify association between maternal and/or child microbiome with child growth and neurodevelopment. Additionally, intervention studies such as use of nutritional supplementation and its impact on the microbiome, growth and neurodevelopment were reviewed.

METHODS

An exhaustive literature search identified 654 relevant citations. After review of abstracts, 557 were eliminated, and 97 remained for full text review. We identified and reported on 42 articles which met inclusion criteria.

RESULTS

Seven studies examined associations between microbiome and neurodevelopment and 36 studies evaluated anthropometric measurements, most commonly weight, and microbiota relationships. One study evaluated both growth and neurodevelopment and microbiota. Fourteen studies evaluated supplemental nutrients. Preterm, low birth weight (LBW), and very low birth weight (VLBW) infants were most studied. Findings were inconclusive for consistent associations between microbiota and growth and neurodevelopment. Further, there were no consistent conclusive changes with prescribed treatment interventions.

DISCUSSION

There is a need for high-quality longitudinal studies evaluating repeated developmental assessment measures using consistent microbial analysis techniques to inform conclusions regarding the association between microbiome and infant and child growth and neurodevelopment. Additional intervention studies that may mitigate dysbiosis are warranted.

Maternal microbe-specific modulation of the offspring microbiome and development during pregnancy and lactation

The maternal microbiome is essential for the healthy growth and development of offspring and has long-term effects later in life. Recent advances indicate that the maternal microbiome begins to regulate fetal health and development during pregnancy. Furthermore, the maternal microbiome continues to affect early microbial colonization via birth and breastfeeding. Compelling evidence indicates that the maternal microbiome is involved in the regulation of immune and brain development and affects the risk of related diseases. Modulating offspring development by maternal diet and probiotic intervention during pregnancy and breastfeeding could be a promising therapy in the future. In this review, we summarize and discuss the current understanding of maternal microbiota development, perinatal microbial metabolite transfer, mother-to-infant microbial transmission during/after birth and its association with immune and brain development as well as corresponding diseases.

Role of the Gut Microbiota in the Increased Infant Body Mass Index Induced by Gestational Diabetes Mellitus

The connection between gestational diabetes mellitus (GDM) and the offspring's development, such as obesity, is well established. Emerging evidence indicates that the microbiota of the neonate's meconium is associated with maternal GDM status. To explore whether the association between GDM and infant body mass index (BMI) in early childhood is affected by the meconium microbiota, we recruited 120 mothers (60 healthy women and 60 with GDM) and their newborns from the Women's Hospital of Nanjing Medical University. Meconium of 120 neonates was collected within a few hours after birth and sequenced using 16S rRNA sequencing analysis. Children's BMI was measured at 12 months of age. The results revealed that infants born to mothers with GDM had increased BMI Z-scores at 12 months old and that the β-diversity of their meconium microbiota was reduced. Several genera were observed to be significantly different between the GDM and control groups. The genus Burkholderia-Caballeronia-Paraburkholderia and an untitled genus in the family Enterobacteriaceae enriched in neonates born to healthy mothers were found to be negatively associated with infant BMI by using regression analysis. A coabundance group depleted in the GDM group was correlated negatively with 12-month BMI and mediated 21.65% of the association between GDM and infant BMI by mediation analyses. This study provided evidence for the associations among maternal GDM, the meconium microbiota, and infant BMI. Maternal GDM was demonstrated to affect infant BMI, mediated by the gut microbiome. Gut microbiome interventions might represent a novel technique to decrease the risk of GDM-induced childhood obesity. IMPORTANCE Using 16S rRNA sequencing analysis, regression analysis and mediation analysis were used to explore whether maternal gestational diabetes mellitus (GDM) changed the function and composition of the meconium microbiota and whether this explained the GDM-induced alterations of infant body mass index (BMI). This study showed that gut microbiome dysbiosis induced by maternal GDM might play an important role in the increased infant BMI during the first 12 months of life. Therefore, gut microbiome interventions might represent a novel technique to decrease the risk of GDM-induced childhood obesity.

Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance

Non-nutritive sweeteners (NNS) are commonly integrated into human diet and presumed to be inert; however, animal studies suggest that they may impact the microbiome and downstream glycemic responses. We causally assessed NNS impacts in humans and their microbiomes in a randomized-controlled trial encompassing 120 healthy adults, administered saccharin, sucralose, aspartame, and stevia sachets for 2 weeks in doses lower than the acceptable daily intake, compared with controls receiving sachet-contained vehicle glucose or no supplement. As groups, each administered NNS distinctly altered stool and oral microbiome and plasma metabolome, whereas saccharin and sucralose significantly impaired glycemic responses. Importantly, gnotobiotic mice conventionalized with microbiomes from multiple top and bottom responders of each of the four NNS-supplemented groups featured glycemic responses largely reflecting those noted in respective human donors, which were preempted by distinct microbial signals, as exemplified by sucralose. Collectively, human NNS consumption may induce person-specific, microbiome-dependent glycemic alterations, necessitating future assessment of clinical implications.

Non-nutritive sweeteners and their impacts on the gut microbiome and host physiology

Non-nutritive sweeteners (NNS) are broadly incorporated into foods, especially those representing a growing share of the beverage market. NNS are viewed as a noncaloric and desirable alternative to sugar-based sweeteners and are thought to contribute to reducing overall caloric intake. While these compounds have been studied extensively and have long been considered inert, new research has presented a different view and raises new questions about the effects of NNS on human physiology. Namely, the influence on glucose responses, the gastrointestinal epithelium, and the gut microbiome. As the gut microbiome is now recognized as a major mediator of human health and perturbations to this community are generally associated with negative health trajectories or overt disease, interactions between NNS and the gut microbiome are of increasing interest to clinicians and researchers. Several NNS compounds are now hypothesized to affect human physiology by modulating the gut microbiome, though the mechanism for this action remains unclear. The purpose of this review is to discuss the history and current knowledge of NNS, their reported utility and effects on host physiology and the gut microbiome, and describes a model for investigating the underlying mechanism behind reported effects of NNS on the gut microbiome.

Dietary exposure to low-calorie sweeteners in a sample of Brazilian pregnant women

The dietary exposure to low-calorie sweeteners (LCS) was estimated in a sample of pregnant Brazilian women. Consumption data were obtained with a 24-h Dietary Recall interview. Because of the uncertainty in assessing foods with LCS, they were classified into three scenarios to ensure inclusion of the 15 LCS allowed for use in Brazil: ranging from a less to a more conservative scenario. The concentration of LCS was estimated using the amount declared on the label or the maximum permitted levels and analytical determination data for table-top sweeteners. The frequency of consumption was higher for acesulfame-K, aspartame, and cyclamate. The food groups contributing the most to the consumption of LCS were non-alcoholic beverages, table-top sweeteners, confectionary and desserts. The level of dietary exposure to LCS was within the safety limit. However, continued efforts to monitor their dietary exposure are necessary given the limitations highlighted in this study.

Maternal consumption of a fermented diet protects offspring against intestinal inflammation by regulating the gut microbiota

The neonatal intestinal tract is immature and can be easily infected by pathogens causing inflammation. Maternal diet manipulation is a promising nutritional strategy to enhance the gut health of offspring. A fermented diet is a gut microbiota targeting diet containing live probiotics and their metabolites, which benefit the gut and overall health host. However, it remains unclear how a maternal fermented diet (MFD) affects neonatal intestinal inflammation. Here, in vivo and in vitro models together with multi-omics analysis were applied to investigate the impacts and the underlying mechanism through which an MFD prevents from gut inflammation in neonates. An MFD remarkably improved the performance of both sows and piglets and significantly altered the gut microbiome and milk metabolome of sows. In addition, the MFD significantly accelerated the maturation of the gut microbiota of neonates and increased the abundance of gut Lactobacillus and the microbial functions of amino acid-related enzymes and glucose metabolism on the weaning day. Notably, the MFD reduced susceptibility to colonic inflammation in offspring. The fecal microbiota of sows was then transplanted into mouse dams and it was found that the mouse dams and pups in the MFD group alleviated the LPS-induced decrease in gut Lactobacillus abundance and barrier injury. Milk L-glutamine (GLN) and gut Lactobacillus reuteri (LR) were found as two of the main MFD-induced sow effectors that contributed to the gut health of piglets. The properties of LR and GLN in modulating gut microbiota and alleviating colonic inflammation by inhibiting the phosphorylation of p38 and JNK and activation of Caspase 3 were further verified. These findings provide the first data revealing that an MFD drives neonate gut microbiota development and ameliorates the colonic inflammation by regulating the gut microbiota. This fundamental evidence might provide references for modulating maternal nutrition to enhance early-life gut health and prevent gut inflammation.

NMR Metabolomics Reveal Urine Markers of Microbiome Diversity and Identify Benzoate Metabolism as a Mediator between High Microbial Alpha Diversity and Metabolic Health

Microbial metabolites measured using NMR may serve as markers for physiological or pathological host–microbe interactions and possibly mediate the beneficial effects of microbiome diversity. Yet, comprehensive analyses of gut microbiome data and the urine NMR metabolome from large general population cohorts are missing. Here, we report the associations between gut microbiota abundances or metrics of alpha diversity, quantified from stool samples using 16S rRNA gene sequencing, with targeted urine NMR metabolites measures from 951 participants of the Study of Health in Pomerania (SHIP). We detected significant genus–metabolite associations for hippurate, succinate, indoxyl sulfate, and formate. Moreover, while replicating the previously reported association between hippurate and measures of alpha diversity, we identified formate and 4-hydroxyphenylacetate as novel markers of gut microbiome alpha diversity. Next, we predicted the urinary concentrations of each metabolite using genus abundances via an elastic net regression methodology. We found profound associations of the microbiome-based hippurate prediction score with markers of liver injury, inflammation, and metabolic health. Moreover, the microbiome-based prediction score for hippurate completely mediated the clinical association pattern of microbial diversity, hinting at a role of benzoate metabolism underlying the positive associations between high alpha diversity and healthy states. In conclusion, large-scale NMR urine metabolomics delivered novel insights into metabolic host–microbiome interactions, identifying pathways of benzoate metabolism as relevant candidates mediating the beneficial health effects of high microbial alpha diversity.

The Maternal-Fetal Gut Microbiota Axis: Physiological Changes, Dietary Influence, and Modulation Possibilities

The prenatal period and the first years of life have a significant impact on the health issues and life quality of an individual. The appropriate development of the immune system and the central nervous system are thought to be major critical determining events. In parallel to these, establishing an early intestinal microbiota community is another important factor for future well-being interfering with prenatal and postnatal developmental processes. This review aims at summarizing the main characteristics of maternal gut microbiota and its possible transmission to the offspring, thereby affecting fetal and/or neonatal development and health. Since maternal dietary factors are potential modulators of the maternal-fetal microbiota axis, we will outline current knowledge on the impact of certain diets, nutritional factors, and nutritional modulators during pregnancy on offspring's microbiota and health.

The microbiota-gut-brain axis: pathways to better brain health. Perspectives on what we know, what we need to investigate and how to put knowledge into practice

The gut and brain link via various metabolic and signalling pathways, each with the potential to influence mental, brain and cognitive health. Over the past decade, the involvement of the gut microbiota in gut-brain communication has become the focus of increased scientific interest, establishing the microbiota-gut-brain axis as a field of research. There is a growing number of association studies exploring the gut microbiota's possible role in memory, learning, anxiety, stress, neurodevelopmental and neurodegenerative disorders. Consequently, attention is now turning to how the microbiota can become the target of nutritional and therapeutic strategies for improved brain health and well-being. However, while such strategies that target the gut microbiota to influence brain health and function are currently under development with varying levels of success, still very little is yet known about the triggers and mechanisms underlying the gut microbiota's apparent influence on cognitive or brain function and most evidence comes from pre-clinical studies rather than well controlled clinical trials/investigations. Filling the knowledge gaps requires establishing a standardised methodology for human studies, including strong guidance for specific focus areas of the microbiota-gut-brain axis, the need for more extensive biological sample analyses, and identification of relevant biomarkers. Other urgent requirements are new advanced models for in vitro and in vivo studies of relevant mechanisms, and a greater focus on omics technologies with supporting bioinformatics resources (training, tools) to efficiently translate study findings, as well as the identification of relevant targets in study populations. The key to building a validated evidence base rely on increasing knowledge sharing and multi-disciplinary collaborations, along with continued public-private funding support. This will allow microbiota-gut-brain axis research to move to its next phase so we can identify realistic opportunities to modulate the microbiota for better brain health.

Infant gut microbiota restoration: state of the art

The gut microbiota has a central role in the programming of the host's metabolism and immune function, with both immediate and long-term health consequences. Recent years have witnessed an accumulation of understanding of the process of the colonization and development of the gut microbiota in infants. The natural gut microbiota colonization during birth is frequently disrupted due to C-section birth or intrapartum or postpartum antibiotic exposure, and consequently aberrant gut microbiota development is common. On a positive note, research has shown that restoration of normal gut microbiota development is feasible. We discuss here the current understanding of the infant microbiota, provide an overview of the sources of disturbances, and critically evaluate the evidence on early life gut microbiota restoration for improved health outcomes by analyzing published data from infant gut microbiota restoration studies.

Diet Beverage Intake during Lactation and Associations with Infant Outcomes in the Infant Feeding Practices Study II

Consumption of diet beverages (DB) containing low-calorie sweeteners (LCS) is widespread in the United States. LCS are ingested by nursing infants upon maternal DB consumption, which may impact infants' weight and health. This study aims to examine cross-sectional associations between infants' LCS exposure via maternal DB intake during lactation and infants' health outcomes. Six hundred and eighty-two mother-infant dyads at three months postpartum, from the Infant Feeding Practices Study II, 2005-2007, were included in the analysis. Maternal DB consumption during lactation was estimated using the serving size and frequency of DB consumption reported on the diet history questionnaire. Infants' LCS exposure was estimated by multiplying maternal DB consumption and breastfeeding intensity. Infant outcomes included weight, weight-for-age and BMI-for-age z-scores, overweight, and gastrointestinal (GI) symptoms including diarrhea, reflux, and vomiting. Associations between infants' LCS exposure and continuous and categorical outcomes were examined using linear and logistic regressions adjusting for confounders, respectively. Forty-three percent of lactating women reported DB consumption. While no significant associations were observed between infants' LCS exposure and BMI-for-age or risk of overweight, infants' LCS exposure was associated with a 2.78-fold increased risk of vomiting (95% confidence interval 1.05-7.34). Potential adverse effects of LCS exposure on GI symptoms require further study, and null findings on infant weight should be interpreted with caution, given the small sample size. Additional research is needed to inform recommendations for or against DB consumption during lactation.

Early-life gut microbiota and its connection to metabolic health in children: Perspective on ecological drivers and need for quantitative approach

The colonisation and development of the gut microbiota has been implicated in paediatric metabolic disorders via its powerful effect on host metabolic and immune homeostasis. Here we summarise the evidence from human studies on the early gut microbiota and paediatric overweight and obesity. Manipulation of the early gut microbiota may represent a promising target for countering the burgeoning metabolic disorders in the paediatric population, provided the assembly patterns of microbiota and their health consequences can be decoded. Therefore, in this review, we pay particular attention to the important ecological drivers affecting the community dynamics of the early gut microbiota. We then discuss the knowledge gaps in commonly studied exposures linking the gut microbiota to metabolic disorders, especially regarding maternal factors and antibiotic use. This review also attempts to give directions for future studies aiming to identify predictive and corrective measures for paediatric metabolic disorders based on the gut microbiota. Gut microbiota; Metabolism; Paediatric overweight and obesity; Ecological driver; Dynamics; Infants.

Impact of Early Life Nutrition on Children's Immune System and Noncommunicable Diseases Through Its Effects on the Bacterial Microbiome, Virome and Mycobiome

The first 1000 days of life, including the intrauterine period, are regarded as a fundamental stepping stone for the development of a human. Unequivocally, nutrition during this period plays a key role on the proper development of a child, both directly through the intake of essential nutrients and indirectly by affecting the composition of the gut microbiota. The gut microbiota, including bacteria, viruses, fungi, protists and other microorganisms, is a highly modifiable and adaptive system that is influenced by diet, lifestyle, medicinal products and the environment. Reversely, it affects the immune system in multiple complex ways. Many noncommunicable diseases (NCDs) associated with dysbiosis are "programmed" during childhood. Nutrition is a potent determinant of the children's microbiota composition and maturation and, therefore, a strong determinant of the NCDs' programming. In this review we explore the interplay between nutrition during the first 1000 days of life, the gut microbiota, virome and mycobiome composition and the development of NCDs.