Differences in the gut microbiota of women according to ultra-processed food consumption

Socioeconomic adversity, maternal nutrition, and the prenatal programming of offspring cognition and language at two years of age through maternal inflammation

Increasing rates of child neurodevelopmental vulnerability are a significant public health challenge. The adverse effect of socioeconomic adversity on offspring cognition may be mediated through elevated prenatal maternal systemic inflammation, but the role of modifiable antecedents such as maternal nutrition has not yet been clarified. This study aimed to examine (1) whether prenatal factors, with an emphasis on maternal nutrition, were associated with prenatal maternal systemic inflammation at 28 weeks' gestation, including the metabolomic marker glycoprotein acetyls (GlycA); (2) the extent to which the association between prenatal maternal nutrition and child cognition and language at age two years was mediated by elevated maternal inflammation in pregnancy; (3) the extent to which the associations between prenatal socioeconomic adversity and child neurodevelopment were mediated through prenatal maternal nutrition and GlycA levels. We used a prospective population-derived pre-birth longitudinal cohort study, the Barwon Infant Study (Barwon region of Victoria, Australia), where 1074 mother-child pairs were recruited by 28 weeks' gestation using an unselected sampling frame. Exposures included prenatal factors such as maternal diet measured by a validated food frequency questionnaire at 28 weeks' gestation and dietary patterns determined by principal component analysis. The main outcome measures were maternal inflammatory biomarkers (GlycA and hsCRP levels) at 28 weeks' gestation, and offspring Bayley-III cognition and language scores at age two years. Results showed that the 'modern wholefoods' and 'processed' maternal dietary patterns were independently associated with reduced and elevated maternal inflammation respectively (GlycA or hsCRP p < 0.001), and also with higher and reduced offspring Bayley-III scores respectively (cognition p ≤ 0.004, language p ≤ 0.009). Associations between dietary patterns and offspring cognition and language were partially mediated by higher maternal GlycA (indirect effect: cognition p ≤ 0.036, language p ≤ 0.05), but were less evident for hsCRP. The maternal dietary patterns mediated 22 % of the association between socioeconomic adversity (lower maternal education and/or lower household income vs otherwise) and poorer offspring cognition (indirect effect p = 0.001). Variation in prenatal GlycA levels that were independent of these dietary measures appeared less important. In conclusion, modifiable prenatal maternal dietary patterns were associated with adverse child neurocognitive outcomes through their effect on maternal inflammation (GlycA). Maternal diet may partially explain the association between socioeconomic adversity and child neurocognitive vulnerability. Maternal diet-by-inflammation pathways are an attractive target for future intervention studies.

Feeding gut microbes to nourish the brain: unravelling the diet-microbiota-gut-brain axis

The prevalence of brain disorders, including stress-related neuropsychiatric disorders and conditions with cognitive dysfunction, is rising. Poor dietary habits contribute substantially to this accelerating trend. Conversely, healthy dietary intake supports mood and cognitive performance. Recently, the communication between the microorganisms within the gastrointestinal tract and the brain along the gut-brain axis has gained prominence as a potential tractable target to modulate brain health. The composition and function of the gut microbiota is robustly influenced by dietary factors to alter gut-brain signalling. To reflect this interconnection between diet, gut microbiota and brain functioning, we propose that a diet-microbiota-gut-brain axis exists that underpins health and well-being. In this Review, we provide a comprehensive overview of the interplay between diet and gut microbiota composition and function and the implications for cognition and emotional functioning. Important diet-induced effects on the gut microbiota for the development, prevention and maintenance of neuropsychiatric disorders are described. The diet-microbiota-gut-brain axis represents an uncharted frontier for brain health diagnostics and therapeutics across the lifespan.

Assessment of Biochemical, Inflammatory Biomarkers and Ultra-Processed Food Consumption in Children with Small Intestinal Bacterial Overgrowth: A Cross-Sectional Study

OBJECTIVE

This study evaluated anthropometric, biochemical, and inflammatory biomarkers, as well as dietary intake in Brazilian children diagnosed with small intestinal bacterial overgrowth (SIBO) and compared them with their counterparts without SIBO.

METHODS

This was a cross-sectional study with 106 children aged 7 to 10 years. A glucose-hydrogen breath test was performed to diagnose small intestinal bacterial overgrowth (SIBO). Anthropometric and dietary characteristics were assessed. Blood samples were collected and serum biochemical parameters and cytokines were measured.

RESULTS

The occurrence of SIBO was 13.2%. Age, BMI, BMI/age WC, BFP, sex and biochemical markers were similar between SIBO-positive and SIBO-negative children (p > 0.05). High consumption of ultra-processed foods tended to be higher in SIBO-positive compared to SIBO-negative children (47.8 ± 8.2 vs. 42.6 ± 9.5, p = 0.06). Serum levels of IL-17 were higher in SIBO-positive than in SIBO-negative children [69.5 (5.4-125.7) vs. 53.4 (2.3-157.7), p = 0.03], while serum levels of IL-10 were lower in SIBO-positive than in SIBO-negative children [2.3 (0.6-7.2) vs. 5.7 (0.5-30.8), p = 0.04]. Finally, in a logistic regression adjusted for sex, BMI and age, consumption of ultra-processed foods (p = 0.03) and IL-6 levels (p = 0.003) were found to contribute to the occurrence of SIBO.

CONCLUSION

this study identified for the first time an occurrence of 13% of SIBO in children living in the northeastern region of Brazil and showed that consumption of ultra-processed foods and serum levels of IL-6 may influence the occurrence of the SIBO in the pediatrics population.

Ultra-Processed Foods: A Narrative Review of the Impact on the Human Gut Microbiome and Variations in Classification Methods

Ultra-processed foods (UPFs) are foods that are industrially processed and are often pre-packaged, convenient, energy-dense, and nutrient-poor. UPFs are widespread in the current Western diet and their proposed contribution to non-communicable diseases such as obesity and cardiovascular disease is supported by numerous studies. UPFs are hypothesized to affect the body in multiple ways, including by inducing changes in the gut microbiome. This review summarizes the available research on the effect of UPFs on the gut microbiome. We also review current usage of the NOVA food classification system in randomized controlled trials and observational studies and how its implementation effects UPF research. Despite some differences in methodology between studies, results often associate UPF consumption with a number of negative health consequences. There are attempts to standardize a UPF classification system; however, reaching and implementing a consensus is difficult. Future studies focusing on the mechanisms by which UPFs effect the body, including through the microbiome and metabolome, will be essential to refine our understanding of the effects of UPFs on human health.

Ultra-processed food consumption and cardiovascular events rate: An analysis from Isfahan Cohort Study (ICS)

BACKGROUND AND AIMS

The contribution of ultra-processed foods (UPFs) to daily energy intake and, therefore, their health effects may vary between countries. We aimed to investigate the association between UPFs and the incidence risk of cardiovascular events (CVEs) and cardiovascular mortality in the Isfahan cohort study.

METHODS AND RESULTS

In 2001, 6504 participants aged ≥35 years were enrolled and followed until 2017. Dietary intake was assessed using a validated food frequency questionnaire, and the NOVA system was applied for UPF classification. Any new case of CVE, including fatal and non-fatal myocardial infarction (MI) or stroke, unstable angina (UA), and CVD death, was recorded. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated through Cox proportional hazards regression models. A total number of 819 CVE, 164 MI, 348 UA, 172 strokes, and 181 cardiovascular deaths were recorded during 61352.5 person-years of follow-up. The median (IQR) of UPF consumption was 2.47 (1.00-5.23) times/week. In the fully adjusted model, individuals in the fourth quartile of UPFs had no higher risk for incident MI and UA (HR = 1.12, 95% CI: 0.87, 1.46; P for trend = 0.364), stroke (HR = 0.93, 95% CI: 0.58, 1.46; P for trend = 0.601), cardiovascular mortality (HR = 0.95, 95% CI: 0.61, 1.47; P for trend = 0.596), and CVE (HR = 1.08, 95% CI: 0.88,1.34; P for trend = 0.515) in comparison with those in the first quartile.

CONCLUSION

This mid-term prospective cohort study provides no evidence for a significant association between UPF and CVE risk. Longer studies are required to confirm this association.

Gut microbiota in multiple sclerosis and animal models

Multiple sclerosis (MS) is a chronic central nervous system (CNS) neurodegenerative and neuroinflammatory disease marked by a host immune reaction that targets and destroys the neuronal myelin sheath. MS and correlating animal disease models show comorbidities, including intestinal barrier disruption and alterations of the commensal microbiome. It is accepted that diet plays a crucial role in shaping the microbiota composition and overall gastrointestinal (GI) tract health, suggesting an interplay between nutrition and neuroinflammation via the gut-brain axis. Unfortunately, poor host health and diet lead to microbiota modifications that could lead to significant responses in the host, including inflammation and neurobehavioral changes. Beneficial microbial metabolites are essential for host homeostasis and inflammation control. This review will highlight the importance of the gut microbiota in the context of host inflammatory responses in MS and MS animal models. Additionally, microbial community restoration and how it affects MS and GI barrier integrity will be discussed.

The association between ultra-processed food and common pregnancy adverse outcomes: a dose-response systematic review and meta-analysis

OBJECTIVES

Given the increasing incidence of negative outcomes during pregnancy, our research team conducted a dose-response systematic review and meta-analysis to investigate the relationship between ultra-processed foods (UPFs) consumption and common adverse pregnancy outcomes including gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) infants. UPFs are described as formulations of food substances often modified by chemical processes and then assembled into ready-to-consume hyper-palatable food and drink products using flavors, colors, emulsifiers, and other cosmetic additives. Examples include savory snacks, reconstituted meat products, frozen meals that have already been made, and soft drinks.

METHODS

A comprehensive search was performed using the Scopus, PubMed, and Web of Science databases up to December 2023. We pooled relative risk (RR) and 95% confidence intervals (CI) using a random-effects model.

RESULTS

Our analysis (encompassing 54 studies with 552,686 individuals) revealed a significant association between UPFs intake and increased risks of GDM (RR = 1.19; 95% CI: 1.10, 1.27; I2 = 77.5%; p < 0.001; studies = 44; number of participants = 180,824), PE (RR = 1.28; 95% CI: 1.03, 1.59; I2 = 80.0%; p = 0.025; studies = 12; number of participants = 54,955), while no significant relationships were found for PTB, LBW and SGA infants. Importantly, a 100 g increment in UPFs intake was related to a 27% increase in GDM risk (RR = 1.27; 95% CI: 1.07, 1.51; I2 = 81.0%; p = 0.007; studies = 9; number of participants = 39,812). The non-linear dose-response analysis further indicated a positive, non-linear relationship between UPFs intake and GDM risk Pnonlinearity = 0.034, Pdose-response = 0.034), although no such relationship was observed for PE (Pnonlinearity = 0.696, Pdose-response = 0.812).

CONCLUSION

In summary, both prior to and during pregnancy, chronic and excessive intake of UPFs is associated with an increased risk of GDM and PE. However, further observational studies, particularly among diverse ethnic groups with precise UPFs consumption measurement tools, are imperative for a more comprehensive understanding.

Ultra-processed food and non-communicable diseases in the United Kingdom: A narrative review and thematic synthesis of literature

The social and economic constructs of the United Kingdom (UK) provide a fertile food environment for the dramatic expansion in the ultra-processed food (UPF) market, driving increased UPF consumption. This has coincided with the significant increase in the incidence and prevalence of non-communicable diseases (NCDs) such as obesity, type 2 diabetes, cardiovascular disease, and cancer, with an inherent impact on morbidity and mortality. Our review aims to assess the current epidemiological and public health trends in the United Kingdom, specifically examining consumption of UPFs and subsequent development of NCDs, summarizing existing meta-analytical and experimental approaches. First, we address important socioeconomic and psychosocial domains that may contribute to increased availability and consumption of UPF. Additionally, we explore the putative mechanistic basis for the association between UPFs and NCDs: partly attributable to their energy density, the macro- and micronutrient composition (including high refined carbohydrate, saturated, and trans fats composition, in addition to low fiber and protein content), and artificially engineered additives and other compounds that adversely affect health in inadequately researched pathophysiological pathways. This review highlights the importance of promoting minimally processed diets to both clinical and political decision makers.

Nutritional Criminology: Why the Emerging Research on Ultra-Processed Food Matters to Health and Justice

There is mounting concern over the potential harms associated with ultra-processed foods, including poor mental health and antisocial behavior. Cutting-edge research provides an enhanced understanding of biophysiological mechanisms, including microbiome pathways, and invites a historical reexamination of earlier work that investigated the relationship between nutrition and criminal behavior. Here, in this perspective article, we explore how this emergent research casts new light and greater significance on previous key observations. Despite expanding interest in the field dubbed 'nutritional psychiatry', there has been relatively little attention paid to its relevancy within criminology and the criminal justice system. Since public health practitioners, allied mental health professionals, and policymakers play key roles throughout criminal justice systems, a holistic perspective on both historical and emergent research is critical. While there are many questions to be resolved, the available evidence suggests that nutrition might be an underappreciated factor in prevention and treatment along the criminal justice spectrum. The intersection of nutrition and biopsychosocial health requires transdisciplinary discussions of power structures, industry influence, and marketing issues associated with widespread food and social inequalities. Some of these discussions are already occurring under the banner of 'food crime'. Given the vast societal implications, it is our contention that the subject of nutrition in the multidisciplinary field of criminology-referred to here as nutritional criminology-deserves increased scrutiny. Through combining historical findings and cutting-edge research, we aim to increase awareness of this topic among the broad readership of the journal, with the hopes of generating new hypotheses and collaborations.

Challenges and priorities for researching the gut microbiota in individuals living with anorexia nervosa

OBJECTIVE

The gut microbiota is implicated in several symptoms and biological pathways relevant to anorexia nervosa (AN). Investigations into the role of the gut microbiota in AN are growing, with a specific interest in the changes that occur in response to treatment. Findings suggest that microbial species may be associated with some of the symptoms common in AN, such as depression and gastrointestinal disturbances (GID). Therefore, researchers believe the gut microbiota may have therapeutic relevance. Whilst research in this field is rapidly expanding, the unique considerations relevant to conducting gut microbiota research in individuals with AN must be addressed.

METHOD

We provide an overview of the published literature investigating the relationship between the gut microbiota and symptoms and behaviors present in AN, discuss important challenges in gut microbiota research, and offer recommendations for addressing these. We conclude by summarizing research design priorities for the field to move forward.

RESULTS

Several ways exist to reduce participant burden and accommodate challenges when researching the gut microbiota in individuals with AN.

DISCUSSION

Recommendations from this article are foreseen to encourage scientific rigor and thoughtful protocol planning for microbiota research in AN, including ways to reduce participant burden. Employing such methods will contribute to a better understanding of the role of the gut microbiota in AN pathophysiology and treatment.

PUBLIC SIGNIFICANCE

The field of gut microbiota research is rapidly expanding, including the role of the gut microbiota in anorexia nervosa. Thoughtful planning of future research will ensure appropriate data collection for meaningful interpretation while providing a positive experience for the participant. We present current challenges, recommendations for research design and priorities to facilitate the advancement of research in this field.

Oxidative Stress and Inflammatory Biomarkers Are Related to High Intake of Ultra-Processed Food in Old Adults with Metabolic Syndrome

In the last few decades the consumption of ultra-processed foods (UPFs) worldwide has substantially augmented. Increasing evidence suggests that high UPF consumption is associated with an increase in non-communicable diseases, being overweight, and obesity. The aim of this study was to assess how UPF consumption affects oxidative and inflammatory status in the plasma, neutrophils, and urine of old adults with metabolic syndrome. Participants (n = 92) were classified into two groups according to UPF consumption. Dietary intakes were measured by a validated semi-quantitative 143-item food frequency questionnaire and UPF consumption was determined according to the NOVA classification system. Low UPF consumers showed higher adherence to the Mediterranean diet than high UPF consumers. A high intake of fiber and a high concentration of polyphenols in urine were also observed in subjects with low UPF consumption. Despite the absence of differences in biochemical profile, oxidative and inflammatory biomarkers showed some significant changes. Catalase and superoxide dismutase activities were lower in high UPF consumers, whereas myeloperoxidase activity was higher. ROS production in neutrophils stimulated with zymosan was higher in high UPF consumers than in low UPF consumers. Biomarkers such as xanthine oxidase, tumor necrosis factor α (TNFα), interleukin (IL)-6, IL-15, and leptin levels were higher in participants with high intake of UPF. No differences were found in malondialdehyde and other inflammatory cytokines. The current study evidenced that MetS participants with high UPF consumption have a more pro-oxidant and inflammatory profile than those with low UPF consumption, despite showing similar blood biochemical profiles.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Association between ultra-processed foods and risk of cancer: a systematic review and meta-analysis

Background

Despite increasing evidence that has shown the association of ultra-processed foods (UPFs) with cancer risk, the results remain inconclusive. We, therefore, conducted the meta-analysis to clarify the association by including recently published studies.

Methods

A comprehensive search was conducted in PubMed, Embase, and Web of Science to identify all relevant studies from inception to January 2023. To pool data, fixed-effects or random-effects models were used where appropriate. Subgroup analyses, sensitivity analyses, and publication bias tests were performed.

Results

A total of 13 studies (4 cohort studies and 9 case-control studies) were included in the analysis, with a total of 625,738 participants. The highest UPFs consumption was associated with increased risk of colorectal cancer (OR = 1.23, 95% CI: 1.10-1.38), colon cancer (OR = 1.25, 95% CI: 1.14-1.36), and breast cancer (OR = 1.10, 95% CI: 1.00-1.20) but not rectal cancer (OR = 1.18, 95% CI: 0.97-1.43) and prostate cancer (OR = 1.03, 95% CI: 0.93-1.12). In addition, the subgroup analyses showed that a positive association between UPFs consumption and colorectal cancer was observed among men (OR = 1.31, 95% CI: 1.15-1.50), whereas no significant association was observed among women (OR = 1.10, 95% CI: 0.94-1.29).

Conclusion

The present meta-analysis suggests that high UPFs consumption is associated with a significantly increased risk of certain site-specific cancers, especially the digestive tract and some hormone-related cancers. However, further rigorously designed prospective and experimental studies are needed to better understand causal pathways.

Non-Classical Aspects of Obesity Pathogenesis and Their Relative Clinical Importance for Obesity Treatment

Obesity is a chronic disease and a major public health problem due to its association with non-communicable diseases and all-cause mortality. An increased energy intake and decreased physical activity have been long recognized as the classical parameters that contribute to the development of obesity. However, several other, non-classical factors have also been associated with obesity through various complex mechanisms. Some of them are diet related, such as diet quality, dietary habits and speed of eating. Other factors are non-dietary, such as endocrine-disrupting chemicals, sleep quality and quantity, psychotropic medications and light at night. The scope of the present narrative review is to address these non-classical factors that are implicated in the pathogenesis of obesity, to clarify their potential role in the management of obesity and, where possible, to provide some practical clinical recommendations.