No Difference in Lactoferrin Levels between Metabolically Healthy and Unhealthy Obese Women

Meconium Proteins Involved in Iron Metabolism

The lack of specific biological materials and biomarkers limits our knowledge of the mechanisms underlying intrauterine regulation of iron supply to the fetus. Determining the meconium content of proteins commonly used in the laboratory to assess the transport, storage, and distribution of iron in the body may elucidate their roles in fetal development. Ferritin, transferrin, haptoglobin, ceruloplasmin, lactoferrin, myeloperoxidase (MPO), neutrophil gelatinase-associated lipocalin (NGAL), and calprotectin were determined by ELISA in meconium samples obtained from 122 neonates. There were strong correlations between the meconium concentrations of haptoglobin, transferrin, and NGAL (p < 0.05). Meconium concentrations of ferritin were several-fold higher than the concentrations of the other proteins, with the exception of calprotectin whose concentration was approximately three-fold higher than that of ferritin. Meconium ceruloplasmin concentration significantly correlated with the concentrations of MPO, NGAL, lactoferrin, and calprotectin. Correlations between the meconium concentrations of haptoglobin, transferrin, and NGAL may reflect their collaborative involvement in the storage and transport of iron in the intrauterine environment in line with their recognized biological properties. High meconium concentrations of ferritin may provide information about the demand for iron and its utilization by the fetus. The associations between ceruloplasmin and neutrophil proteins may indicate the involvement of ceruloplasmin in the regulation of neutrophil activity in the intrauterine environment.

Differences in the levels of inflammatory markers between metabolically healthy obese and other obesity phenotypes in adults: A systematic review and meta-analysis

AIMS

The aim of this study was to systematically review and analyze differences in the levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) comparing metabolically healthy but obese (MHO) with metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), and metabolically unhealthy obese (MUO) subjects.

DATA SYNTHESIS

We searched PubMed, Embase, Web of Science, and Scopus for studies that matched the relevant search terms. Differences in inflammatory marker levels between MHO and the other three phenotypes were pooled as standardized mean differences (SMD) or differences of medians (DM) using a random-effects model. We included 91 studies reporting data on 435,007 individuals. The CRP levels were higher in MHO than in MHNO subjects (SMD = 0.63, 95% CI: 0.49, 0.76; DM = 0.83 mg/L, 95% CI: 0.56, 1.11). The CRP levels were higher in MHO than in MUNO subjects (SMD = 0.16, 95% CI: 0.05, 0.28; DM = 0.39 mg/L, 95% CI: 0.09, 0.69). The CRP levels were lower in MHO than in MUO individuals (SMD = -0.43, 95% CI: -0.54, -0.31; DM = -0.82 mg/L, 95% CI: -1.16, -0.48). The IL-6 levels in MHO were higher than in MHNO while lower than in MUO subjects. The TNF-α levels in MHO were higher than in MHNO individuals.

CONCLUSIONS

This review provides evidence that CRP levels in MHO are higher than in MHNO and MUNO subjects but lower than in MUO individuals. Additionally, IL-6 levels in MHO are higher than in MHNO but lower than in MUO subjects, and TNF-α levels in MHO are higher than in MHNO individuals.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO number: CRD42021234948.

To Boost or to Reset: The Role of Lactoferrin in Energy Metabolism

Many pathological conditions, including obesity, diabetes, hypertension, heart disease, and cancer, are associated with abnormal metabolic states. The progressive loss of metabolic control is commonly characterized by insulin resistance, atherogenic dyslipidemia, inflammation, central obesity, and hypertension, a cluster of metabolic dysregulations usually referred to as the "metabolic syndrome". Recently, nutraceuticals have gained attention for the generalized perception that natural substances may be synonymous with health and balance, thus becoming favorable candidates for the adjuvant treatment of metabolic dysregulations. Among nutraceutical proteins, lactoferrin (Lf), an iron-binding glycoprotein of the innate immune system, has been widely recognized for its multifaceted activities and high tolerance. As this review shows, Lf can exert a dual role in human metabolism, either boosting or resetting it under physiological and pathological conditions, respectively. Lf consumption is safe and is associated with several benefits for human health, including the promotion of oral and gastrointestinal homeostasis, control of glucose and lipid metabolism, reduction of systemic inflammation, and regulation of iron absorption and balance. Overall, Lf can be recommended as a promising natural, completely non-toxic adjuvant for application as a long-term prophylaxis in the therapy for metabolic disorders, such as insulin resistance/type II diabetes and the metabolic syndrome.

Prebiotic/probiotic supplementation resulted in reduced visceral fat and mRNA expression associated with adipose tissue inflammation, systemic inflammation, and chronic disease risk

BACKGROUND

Prebiotic/probiotic supplementation represents a viable option for addressing elevated systemic inflammation and chronic disease risk in overweight individuals. The purpose of this study was to determine if 90 days of prebiotic/probiotic supplementation could alter mRNA responsible for inflammation and chronic disease risk in weight-stable overweight adults. Nanostring mRNA analysis (574 plex) was used to survey targets associated with adipose tissue inflammation, systemic inflammation, and chronic disease risk. All protocols were approved by the University IRB, and participants gave written informed consent. Participants were randomly assigned to either placebo (N = 7; rice flour) or combined (N = 8) prebiotic (PreticX® Xylooligosaccharide; 0.8 g/day; ADIP) and probiotic (MegaDuo® Bacillus subtilis HU58 and Bacillus coagulans SC-208; billion CFU/day) supplementation. Participants were diverse population of healthy individuals with the exception of excess body weight. Measurements were made at baseline, 30, 60, and 90 days. Whole-body DXA scans (GE iDXA®; body composition) and blood 574-plex mRNA analysis (Nanostring®) were used to generate primary outcomes. Significance was set to p < 0.05 and adjusted for multiple comparisons where necessary.

RESULTS

Compared to placebo, prebiotic/probiotic supplementation was associated with a 35% reduction in visceral adipose tissue (VAT; p = 0.002) but no change in body weight or overall percent body fat. Prebiotic/probiotic supplementation resulted in significant (p < 0.05), differential expression of 15 mRNA associated with adipose tissue inflammation (GATA3, TNFAIP6, ST2, CMKLR1, and CD9), systemic inflammation (LTF, SOCS1, and SERPING1), and/or chronic disease risk (ARG1, IL-18, CCL4, CEACAM6, ATM, CD80, and LAMP3). We also found 6 additional mRNA that had no obvious relationship to three previous biological functions (CSF1, SRC, ICAM4CD24, CD274, and CLEC6A).

CONCLUSION

The key findings support that 90-day prebiotic/probiotic supplementation may be associated with reduced adipose tissue inflammation, reduced systemic inflammation, and reduced chronic disease risk. Combined with the unexpected finding of reduced VAT, this intervention may have resulted in improved overall health and reduced chronic disease risk.

Gut microbiota of adults with different metabolic phenotypes

OBJECTIVE

The aim of this study was to investigate the gut microbiota of individuals with different metabolic phenotypes and to compare their characteristics.

METHODS

This was a cross-sectional study with 109 adults, classified according to metabolic status, by body mass index, and homeostasis model assessment. Anthropometric and biochemical characteristics and blood pressure were evaluated. Level of physical activity was evaluated by means of a questionnaire, and dietary consumption was evaluated using a 3-d food record. Feces samples were collected from each participant, and gut microbiota profile was analyzed by sequencing of the 16S rRNA gene. The Kruskal-Wallis and χ² tests were used, according to the scale of measurement of the variables, on the statistical program SPSS version 25, with significance level of 5%.

RESULTS

Significantly lower values of saturated fat intake and fasting glycemia were observed in metabolically healthy individuals who were overweight and obese compared with their unhealthy counterparts. Diversity and richness of bacterial communities were lower in individuals who were obese and in the unhealthy phenotype. The genus Eubacterium rectale and genera of the family Prevotellaceae were more abundant in the metabolically healthy obese and metabolically healthy overweight groups than in the metabolically healthy normal weight one, whereas Bifidobacterium was more abundant in the metabolically healthy normal weight group. The genera Coprococcus and Ruminococcus were more abundant in the metabolically healthy overweight group than in the metabolically unhealthy overweight one.

CONCLUSIONS

We observed distinct characteristics in the gut microbiota of different metabolic phenotypes. The intestines of individuals with unhealthy phenotypes hosted inflammation-associated microbiota, with lower butyrate production potential and reduced bacterial diversity.

Associations of Metabolic/Obesity Phenotypes with Insulin Resistance and C-Reactive Protein: Results from the CNTR Study

BACKGROUND

Obesity is a heterogeneous condition in terms of metabolic status. Different obesity phenotypes have various health risks. The aim of this work was to define different subtypes of obesity and investigate their relationship with inflammatory-cardiometabolic abnormalities among Chinese adult twins.

METHODS

The analyses used data from 1113 adult twins in 4 provinces (Shandong, Zhejiang, Jiangsu and Sichuan) from Chinese National Twin Registry (CNTR) which collected detailed information. We defined those with 0 or 1 metabolic syndrome (MetS) components excluding waist circumference as metabolically healthy, and those with waist circumference ≥90 cm (for men) and ≥85 cm (for women) as obese. The two-category obesity status and metabolic states are combined to generate four metabolic/obesity phenotypes. High sensitivity C reactive protein (hsCRP) was measured to assess underlying inflammation and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as surrogate measure of insulin resistance. Mixed-effect linear regression models and fixed-effect linear regression models were used to analyse the correlation between HOMA-IR, hsCRP and different metabolic/obesity phenotypes.

RESULTS

In cross-sectional analyses of 1113 individuals (mean [SD] age, 46.6 [12.9] years; 463 obese [41.6%]), 20.3% obese twins were metabolic healthy and 64.2% non-obese twins were metabolic unhealthy. Serum HOMA-IR level was higher in metabolically unhealthy non-obesity (MUNO) (β=0.42, 95% CI: 0.21-0.64), metabolically healthy obesity (MHO) (β=0.68, 95% CI: 0.36-1.00) and metabolically unhealthy obesity (MUO) (β=0.69, 95% CI: 0.46-0.91) twins, compared with their metabolically healthy non-obesity (MHNO) counterparts. HsCRP was similar between MHO and MUO, which differed significantly to metabolic healthy non-obesity (MHNO).

CONCLUSION

MHO and MUNO phenotypes were common in Chinese twin population. Both phenotypes were associated with elevated IR and hsCRP which may not be benign and need to be concerned.

Recombinant human lactoferrin attenuates the progression of hepatosteatosis and hepatocellular death by regulating iron and lipid homeostasis in ob/ob mice

Lactoferrin (Lf), an iron-binding glycoprotein, has been shown to possess antioxidant and anti-inflammatory properties and exert modulatory effects on lipid homeostasis and non-alcoholic fatty liver disease (NAFLD), but our understanding of its regulatory mechanisms is limited and inconsistent. We used leptin-deficient (ob/ob) mice as the rodent model of NAFLD, and administered recombinant human Lf (4 mg per kg body weight) or control vehicle by intraperitoneal injection to evaluate the hepatoprotective effects of Lf. After 40 days of treatment with Lf, insulin sensitivity and hepatic steatosis in ob/ob mice were significantly improved with the down-regulation of sterol regulatory element binding protein-2 (SREBP2), indicating an improvement in hepatic lipid metabolism and function. We further explored the mechanism, and found that Lf may increase the hepatocellular iron output by targeting the hepcidin-ferroportin (FPn) axis, and then maintains the liver oxidative balance through a nonenzymatic antioxidant system, ultimately suppressing the death of hepatocytes. In addition, the cytoprotective role of Lf may be associated with the inhibition of endoplasmic reticulum (ER) stress and inflammation, promotion of autophagy of damaged hepatocytes and induction of up-regulation of hypoxia inducible factor-1α/vascular endothelial growth factor (HIF-lα/VEGF) to facilitate liver function recovery. These findings suggest that recombinant human Lf might be a potential therapeutic agent for mitigating or delaying the pathological process of NAFLD.