Effects of Probiotic Supplementation Added to a Weight Loss Program on Anthropometric Measures, Body Composition, Eating Behavior, and Related Hormone Levels in Patients with Food Addiction and Weight Regain After Bariatric Surgery: A Randomized Clinical Trial

PURPOSE

Weight regain after metabolic bariatric surgery is a common problem. Food addiction is an eating disorder that can be one of the reasons for weight regain in these patients. This study aimed to evaluate the effects of probiotic supplementation with a weight loss program and cognitive behavioral therapy (CBT) on anthropometric measures, eating behavior, food addiction, and related hormone levels, in patients with food addiction and weight regain after metabolic bariatric surgery.

MATERIALS AND METHODS

This randomized, triple-blind, placebo-controlled clinical trial was conducted on patients with food addiction and weight regain after metabolic bariatric surgery. Participants (n = 50) received a weight loss program and CBT plus probiotic, or placebo for 12 weeks. Then, anthropometric measurements, biochemical markers, eating behavior, and food addiction were assessed.

RESULTS

Weight and body mass index (BMI) decreased significantly in the probiotic group compared to placebo (p = 0.008, p = 0.001, respectively). Fat mass was significantly decreased in the probiotic group (p < 0.001). Moreover, a significant improvement was observed in the probiotic group's eating behavior and food addiction compared to the placebo group (p < 0.001). Serum levels of leptin decreased significantly (p = 0.02), and oxytocin serum levels increased significantly (p = 0.008) in the probiotic group compared to the placebo group.

CONCLUSION

Adding probiotic supplements to the weight loss program and CBT is superior to the weight loss program and CBT alone in improving weight loss, eating behavior, and food addiction in patients with food addiction and weight regain after metabolic bariatric surgery.

Alcohol does not influence trust in others or oxytocin, but increases positive affect and risk-taking: a randomized, controlled, within-subject trial

BACKGROUND

Alcohol consumption to facilitate social interaction is an important drinking motive. Here, we tested whether alcohol influences trust in others via modulation of oxytocin and/or androgens. We also aimed at confirming previously shown alcohol effects on positive affect and risk-taking, because of their role in facilitating social interaction.

METHODS

This randomized, controlled, within-subject, parallel group, alcohol-challenge experiment investigated the effects of alcohol (versus water, both mixed with orange juice) on perceived trustworthiness via salivary oxytocin (primary and secondary endpoint) as well as testosterone, dihydrotestosterone, positive affect, and risk-taking (additional endpoints). We compared 56 male participants in the alcohol condition (1.07 ± 0.18 per mille blood alcohol concentration) with 20 in the control condition.

RESULTS

The group (alcohol versus control condition) × time (before [versus during] versus after drinking) interactions were not significantly associated with perceived trustworthiness (η2 < 0.001) or oxytocin (η2 = 0.003). Bayes factors provided also substantial evidence for the absence of these effects (BF01 = 3.65; BF01 = 7.53). The group × time interactions were related to dihydrotestosterone (η2 = 0.018 with an increase in the control condition) as well as positive affect and risk-taking (η2 = 0.027 and 0.007 with increases in the alcohol condition), but not significantly to testosterone.

DISCUSSION

The results do not verify alcohol effects on perceived trustworthiness or oxytocin in male individuals. However, they indicate that alcohol (versus control) might inhibit an increase in dihydrotestosterone and confirm that alcohol amplifies positive affect and risk-taking. This provides novel mechanistic insight into social facilitation as an alcohol-drinking motive.

Sustainable utilization of apple pomace and its emerging potential for development of functional foods

Apple pomace, a byproduct of apple processing industry, possesses nutritional components which are of great interests for health aspects. Apple pomace is a good source of dietary fiber, minerals, carbohydrates, phenolic, and antioxidant compounds. These bioactive compounds can be extracted by different extraction techniques which have been comprehensively described in this review article. Furthermore, the incorporation of apple pomace as functional ingredients in different food products like bakery items, extrusion-based snacks, meat, dairy, and confectionary products to improve the commercial value and health benefits has been discussed briefly. This review article can be a helpful tool for industrialists, innovative researchers, and waste management authorities to manage the apple waste in an appropriate and sustainable way.

Prevalence and correlates of addictive eating behaviours in a large cohort of Australian adolescents

OBJECTIVE

Research shows highly palatable foods can elicit addictive eating behaviours or 'food addiction'. Early adolescence is theorised to be a vulnerable period for the onset of addictive eating behaviours, yet minimal research has examined this. This study explored the prevalence and correlates of addictive eating behaviours in a large early adolescent sample.

METHODS

6640 Australian adolescents (Mage = 12.7 ± 0.5, 49%F) completed an online survey. Addictive eating was measured with the Child Yale Food Addiction Scale (YFAS-C). Negative-binomial generalised linear models examined associations between addictive eating symptoms and high psychological distress, energy drink consumption, sugar-sweetened beverage (SSB) consumption, alcohol use, and cigarette use.

RESULTS

Mean YFAS-C symptom criteria count was 1.36 ± 1.47 (of 7). 18.3% of participants met 3+ symptoms, 7.5% endorsed impairment and 5.3% met the diagnostic threshold for food addiction. All examined behavioural and mental health variables were significantly associated with addictive eating symptoms. Effects were largest for high psychological distress and cigarette use; with those exhibiting high psychological distress meeting 0.65 more criteria (95%CI = 0.58-0.72, p < 0.001) and those who smoked a cigarette meeting 0.51 more criteria (95%CI = 0.26-0.76, p < 0.001). High psychological distress and consumption of SSB and energy drinks remained significant when modelling all predictors together.

CONCLUSION

In this large adolescent study, addictive eating symptoms were common. Further research should establish directionality and causal mechanisms behind the association between mental ill-health, alcohol and tobacco use, and addictive eating behaviours. Cross-disciplinary prevention initiatives that address shared underlying risk factors for addictive eating and mental ill-health may offer efficient yet substantial public health benefits.

Food addiction, hormones and blood biomarkers in humans: A systematic literature review

BACKGROUND

Food addiction may play a role in rising obesity rates in connection with obesogenic environments and processed food availability, however the concept of food addiction remains controversial. While animal studies show evidence for addictive processes in relation to processed foods, most human studies are psychologically focussed and there is a need to better understand evidence for biological mechanisms of food addiction in humans. Several key hormones are implicated in models of food addiction, due to their key roles in feeding, energy metabolism, stress and addictive behaviours. This systematic literature review examines evidence for relationships between food addiction, hormones and other blood biomarkers.

METHODS

A series of literature searches was performed in Scopus, PsychInfo, MedLine, ProQuest, CINAHL and Web of Science. A total of 3111 articles were found, of which 1045 were duplicates. Articles were included if they contained a psychometric measurement of food addiction, such as the Yale Food Addiction Scale, as well as addressed the association between FA and hormones or blood biomarkers in humans. Articles were assessed for eligibility by two independent reviewers.

RESULTS

Sixteen studies were identified that examined relationships between food addiction and blood biomarkers, published between 2015 and 2021. Significant findings were reported for leptin, ghrelin, cortisol, insulin and glucose, oxytocin, cholesterol, plasma dopamine, thyroid stimulating hormone (TSH), haemoglobin A1c (HbA1c), triglyceride (TG), amylin, tumour necrosis factor alpha (TNF- α) and cholecystokinin (CCK). Methodological issues included small sample sizes and variation in obesity status, sex and mental health-related comorbidities. Due to methodological limitations, definite connections between FA, hormones and other blood biomarkers cannot yet be determined.

CONCLUSION

This systematic review identified preliminary evidence linking FA symptoms to hormones and other blood biomarkers related to feeding, addiction, and stress. However, due to the small number of studies and methodological limitations, further research is needed to evaluate biopsychosocial models of FA and to resolve controversies.

Polysaccharides from apple pomace exhibit anti-fatigue activity through increasing glycogen content

The polysaccharides were isolated from apple pomace by hot-water extraction, and their anti-fatigue activity was evaluated in C2C12 muscle myoblasts and male Kunming mice. The purified polysaccharides from apple pomace (PAP) have a molecular weight of 1.74 × 105 Da and were composed of mannose, rhamnose, glucose, galactose and arabinose. In C2C12 myoblasts, PAP showed no cytotoxicity in the concentrations of 0-300 μg/ml. PAP treatment increased the glycogen content, while the ATP content was not affected in C2C12 myoblasts. Further investigation found that the activity and gene expression of glycogen synthase, rather than glycogen phosphorylase, were upregulated by PAP treatment. The studies in vivo showed that PAP treatment did not affect the food intake and weight again in mice. Importantly, PAP prolonged the exhaustive swimming time, increased hepatic and skeletal muscle glycogen levels, and effectively inhibited the accumulation of blood lactic and blood urea nitrogen in mice. Taken together, the results suggested that PAP exhibit anti-fatigue activity in vitro and in vivo through increasing glycogen content.

High Plasma Oxytocin Levels in Men With Hypersexual Disorder

CONTEXT

Hypersexual disorder (HD) involves excessive, persistent sexual behaviors related to various mood states and the diagnosis compulsive sexual behavior disorder is included as an impulse control disorder in the 11th revision of the International Classification of Diseases. Although the neurobiology behind the disorder is not clear, some studies suggest dysregulated hypothalamic-pituitary-adrenal axis. Oxytocin acts as counterregulatory neuroendocrine hormone to cortisol and is also involved in sexual behavior.

OBJECTIVE

We hypothesized that oxytocin may play a role in the pathophysiology of HD with compensatory actions to cortisol.

DESIGN

Longitudinal.

SETTING

ANOVA clinic (Karolinska University Hospital).

PATIENTS OR OTHER PARTICIPANTS

64 males with HD and 38 age-matched healthy volunteers.

MAIN OUTCOME MEASURES

Plasma oxytocin levels, measured with radioimmunoassay; Hypersexual Disorder Screening Inventory; and Hypersexual Disorder: Current Assessment Scale for assessing hypersexual symptoms.

INTERVENTIONS

A patient subgroup (n = 30) completed the manual-based group-administered cognitive-behavioral therapy (CBT) program for HD, and posttreatment oxytocin levels were measured.

RESULTS

Hypersexual men (n = 64) exhibited significantly higher oxytocin plasma levels (mean ± SD: 31.0 ± 9.9 pM) compared with healthy volunteers (16.9 ± 3.9 pM; P < 0.001). There were significant positive correlations between oxytocin levels and the rating scales measuring hypersexual behavior. Patients who completed CBT treatment (n = 30) had a significant reduction of oxytocin plasma levels from pretreatment (30.5 ± 10.1 pM) to posttreatment (20.2 ± 8.0 pM; P < 0.001).

CONCLUSIONS

The results suggest that the hyperactive oxytocinergic system in hypersexual men may be a compensatory mechanism to attenuate hyperactive stress.

Neural Functions of Hypothalamic Oxytocin and its Regulation

Oxytocin (OT), a nonapeptide, has a variety of functions. Despite extensive studies on OT over past decades, our understanding of its neural functions and their regulation remains incomplete. OT is mainly produced in OT neurons in the supraoptic nucleus (SON), paraventricular nucleus (PVN) and accessory nuclei between the SON and PVN. OT exerts neuromodulatory effects in the brain and spinal cord. While magnocellular OT neurons in the SON and PVN mainly innervate the pituitary and forebrain regions, and parvocellular OT neurons in the PVN innervate brainstem and spinal cord, the two sets of OT neurons have close interactions histologically and functionally. OT expression occurs at early life to promote mental and physical development, while its subsequent decrease in expression in later life stage accompanies aging and diseases. Adaptive changes in this OT system, however, take place under different conditions and upon the maturation of OT release machinery. OT can modulate social recognition and behaviors, learning and memory, emotion, reward, and other higher brain functions. OT also regulates eating and drinking, sleep and wakefulness, nociception and analgesia, sexual behavior, parturition, lactation and other instinctive behaviors. OT regulates the autonomic nervous system, and somatic and specialized senses. Notably, OT can have different modulatory effects on the same function under different conditions. Such divergence may derive from different neural connections, OT receptor gene dimorphism and methylation, and complex interactions with other hormones. In this review, brain functions of OT and their underlying neural mechanisms as well as the perspectives of their clinical usage are presented.

Oxytocin blood concentrations in alcohol use disorder: A cross-sectional, longitudinal, and sex-separated study

Alcohol use disorder (AUD) is a severe illness, for which we lack sufficient mechanistic understanding. Preliminary evidence associates AUD with the oxytocin (OXT) system. Here we investigated alterations in endogenous OXT blood concentrations in patients with AUD and their association with alcohol drinking and prospective course. In sex-separated analyses, OXT serum concentrations of 200 in-patients with AUD (56.5% male; baseline, 24-72 h of abstinence) were compared with those of 240 age-matched healthy controls (55.4% male), investigated longitudinally (follow-up, 5 days later), and tested for associations with alcohol drinking behavior and prospective 24-month alcohol-related hospital readmissions. At baseline, the patients showed increased OXT concentrations relative to controls (men, 156%, P < 0.001; women, 124%, P = 0.002). The elevations normalized at follow-up. In male patients, baseline OXT concentrations correlated positively with alcohol concentration at admission, the amount of alcohol consumption per drinking year, and the number of previous withdrawal treatments (Rho > 0.195, P < 0.044). In beverage type-specific analysis, baseline OXT concentrations correlated with liquor consumption positively in male and negatively in female patients (|Rho| > 0.277, P < 0.017). Higher baseline OXT concentrations predicted more readmissions and fewer days to the first readmission (|Rho| > 0.185, P < 0.050) in male patients. This study provides novel and sex-separated insights into the role of the OXT system in AUD. We identified a mechanism that might underlie the sex-separated choice of beverage type and established that increased OXT concentrations during early abstinence predict a worse outcome in male patients with AUD.

The influence of sleep health on dietary intake: a systematic review and meta-analysis of intervention studies

BACKGROUND

Poor dietary intake increases disease risk, and poor sleep influences diet. This systematic review and meta-analysis of intervention studies aimed to evaluate the effect of sleep health on dietary intake in adults.

METHODS

Five online databases were used to identify studies published between 1970 and 2019. Included studies were interventions that modified sleep and reported dietary outcomes.

RESULTS

Fifty four full texts were assessed and 24 publications were included. Following risk of bias appraisal, data were narratively summarised and a sub-group of studies (n = 15) was meta-analysed to determine the effect of sleep on dietary intake. One intervention modified sleep timing and 23 modified duration. Sleep duration was partially restricted (≤5.5 h night^-1 ) (n = 16), totally restricted (n = 4), partially and totally restricted (n = 1), and extended (n = 2). Dietary outcomes were energy intake (n = 24), carbohydrate, fat, protein intake (n = 20), single nutrient intake (n = 5), diet quality (n = 1) and food types (n = 1). Meta-analysis indicated partial sleep restriction results in higher energy intake in intervention compared with control [standardised mean difference (SMD) = 0.37; 95% confidence interval (CI) = 0.21-0.52; P < 0.001], with a mean difference of 204 kcal (95% CI = 112-295; P < 0.001) in daily energy intake, and a higher percentage of energy from fat, protein, carbohydrate (fat: SMD = 0.33; 95% CI = 0.16-0.51; P < 0.001; protein: SMD = 0.30, 95% CI = 0.12-0.47, P = 0.001; carbohydrate: SMD = 0.22, 95% CI = 0.04-0.39, P = 0.014).

CONCLUSIONS

Partial sleep restriction with duration of ≤5.5 h day^-1 increases daily energy intake, as well as fat, protein and carbohydrate intake. Further research is needed to determine the relationship between other dimensions of sleep health and dietary intake.

Is weight status associated with peripheral levels of oxytocin? A pilot study in healthy women

The neuropeptide oxytocin is best known for its role during parturition and the milk-let down reflex. Recent evidence identifies a role for oxytocin in eating behaviour. After oxytocin administration, caloric intake is reduced with stronger inhibitory effects in individuals with obesity. Whether the experience of visual food cues affects secretion or circulating levels of oxytocin is unknown. This pilot study had three aims: 1) to measure fasting appetite hormones with a focus on plasma oxytocin concentrations; 2) determine whether healthy vs. hyperpalatable visual food cues differentially altered plasma oxytocin; and 3) assess whether appetite hormone responses to healthy vs. hyperpalatable food images depended on weight or food addiction status. Eighteen healthy women of varying weight status, with/without self-reported food addiction were recruited. Study participants completed a set of standardised questionnaires, including Yale Food Addiction Scale, and attended a one-off experimental session. Blood was collected before and after viewing two sets of food images (healthy and hyperpalatable foods). Participants were randomly allocated in a crossover design to view either healthy images or hyperpalatable foods first. A positive correlation between BMI and plasma oxytocin was found (r² = 0.32, p = 0.021) at baseline. Oxytocin levels were higher, and cholecystokinin levels lower, in food addicted (n = 6) vs. non-food addicted females (p = 0.015 and p<0.001, respectively). There were no significant changes (p>0.05) in plasma oxytocin levels in response to either healthy or hyperpalatable food images. Given that endogenous oxytocin administration tends to suppress eating behaviour; these data indicate that oxytocin receptor desensitization or oxytocin resistance may be important factors in the pathogenesis of obesity and food addiction. However, further studies in larger samples are needed to determine if peripheral oxytocin is responsive to visual food cues.

Demographic, sampling- and assay-related confounders of endogenous oxytocin concentrations: A systematic review and meta-analysis

Studies on endogenous oxytocin concentrations are often criticized for the debatable comparability between specimens and the variation in reported values. We performed meta-regressions on k = 229 studies (n = 12 741 participants), testing whether specimen, extraction, sex, age, time of day, or fasting instructions influenced oxytocin measurements. Predicted oxytocin concentrations differed depending on specimen and extraction: Measurements were extremely high in unextracted blood, compared to extracted blood and other specimens. Measurements were higher in samples with more female participants and higher age. Instructions not to smoke before sampling were correlated with higher oxytocin in unextracted samples. There was no impact of instructions to refrain from eating, drinking, consume caffeine, alcohol or exercising. Oxytocin concentrations increased from morning to afternoon. Our results showed that oxytocin is differentially reflected in blood, saliva, urine and cerebrospinal fluid. Extraction impacts oxytocin measurements, particularly in blood. Considering relevant confounders might increase comparability between studies.

The relationship between oxytocin, dietary intake and feeding: A systematic review and meta-analysis of studies in mice and rats

The neuropeptide oxytocin has been associated with food intake and feeding behaviour. This systematic review aimed to investigate the impact of oxytocin on dietary intake and feeding behaviour in rodent studies. Six electronic databases were searched to identify published studies to April 2018. Preclinical studies in mice and rats were included if they reported: (1) a dietary measure (i.e. food or nutrient and/or behaviour (2) an oxytocin measure, and (3) relationship between the two measures. A total of 75 articles (n = 246 experiments) were included, and study quality appraised. The majority of studies were carried out in males (87%). The top three oxytocin outcomes assessed were: exogenous oxytocin administration (n = 126), oxytocin-receptor antagonist administration (n = 46) and oxytocin gene deletion (n = 29). Meta-analysis of exogenous studies in mice (3 studies, n = 43 comparisons) and rats (n = 8 studies, n = 82 comparisons) showed an overall decrease in food intake with maximum effect shown at 2 h post-administration.

The Neuropeptide Hormone Oxytocin in Eating Disorders

PURPOSE OF REVIEW

The neurohormone oxytocin (OXT) impacts food intake as well as cognitive, emotional, and social functioning-all of which are central to eating disorder (ED) pathology across the weight spectrum. Here, we review findings on endogenous OXT levels and their relationship to ED pathology, the impact of exogenous OXT on mechanisms that drive ED presentation and chronicity, and the potential role of genetic predispositions in the OXT-ED link.

RECENT FINDINGS

Current findings suggest a role of the OXT system in the pathophysiology of anorexia nervosa. In individuals with bulimia nervosa, endogenous OXT levels were comparable to those of healthy controls, and exogenous OXT reduced food intake. Studies in other ED are lacking. However, genetic studies suggest a broad role of the OXT system in influencing ED pathology. Highlighting findings on why OXT represents a potential biomarker of and treatment target for ED, we advocate for a systematic research approach spanning the entire ED spectrum.