The solution properties of galactomannan after simulated digestion of guar fortified bread predict the extent of postprandial insulin reduction in healthy adult overweight subjects.

Coil overlap occurs when random coil polysaccharides such as cereal beta-glucan or galactomannan in solution are abundant enough and large enough to entangle with one another to form networks. It was recently shown that this concept applied to in vitro digested cereal-based foods could predict the efficacy of the food to reduce postprandial glycaemia. In the current study we further investigate the role of coil overlap for prediction of glycaemic and insulinaemic responses using four guar fortified breads (10-15% wheat flour replacement level) with galactomannans of different weight-average molecular weight (Mw). The breads, including a wheat flour control, were tested in a randomised crossover study in 12 overweight adults. Addition of guar reduced postprandial serum insulin, but not glucose responses. The extent of postprandial insulin reduction correlated with the solution properties of galactomannan after in vitro digestion. A significantly greater reduction in insulin response was observed for two of the breads where the galactomannan Mw and concentration in solution after in vitro digestion was above coil overlap, in contrast to two other breads, which resulted in digests containing galactomannan below coil overlap and a significantly lower reduction of postprandial insulin. Further in vitro digestion experiments focusing on amylolysis of starch with kinetic modelling showed a greater proportion of slowly digested starch in breads with galactomannan above coil overlap than below. A combination of the molecular weight of dietary fibre in a food and its soluble concentration are key parameters explaining its physiological efficiency in the upper gastrointestinal tract.

Anxiety and depression in patients with self-reported food hypersensitivity.

OBJECTIVE: Self-reported food hypersensitivity (SFH) is common. Psychological factors are assumed to be associated. We assessed anxiety and depression in SFH patients, using both questionnaires and interview. METHODS: Consecutive patients (n=130) and randomly selected healthy volunteers (n=75) completed the Hospital Anxiety and Depression Scale (HADS), the neuroticism scale of the Eysenck Personality Questionnaire (EPQ-N) and the General Health Questionnaire (GHQ). Seventy-six of the patients were also interviewed by use of the Mini International Neuropsychiatric Interview and the Montgomery-Aasberg Depression Rating Scale. All patients underwent extensive allergological, gastroenterological and dietary examinations. RESULTS: According to interviews, 57% of patients fulfilled the DSM-IV criteria for at least one psychiatric disorder. Anxiety disorders (34%) and depression (16%) predominated. According to questionnaires, patients scored significantly higher than controls on all psychometric scales except for depression (HADS). We also found an underreporting of depression in HADS compared with interviews (2.5% vs. 16%, P=.001). Food hypersensitivity was rarely confirmed by provocation tests (8%). Eighty-nine percent of the patients had irritable bowel syndrome. CONCLUSIONS: Anxiety and depression are common in patients with IBS-like complaints self-attributed to food hypersensitivity. Anxiety disorders predominate. In this setting, depression may be underreported by HADS.

Gastrointestinal food hypersensitivity: symptoms, diagnosis and provocation tests.

As many as 25% of the general population in Western countries believe that they suffer from adverse reactions to food. However, the actual prevalence of food allergy is much lower. Food-induced allergic reactions cause a variety of symptoms including cutaneous, gastrointestinal and respiratory tract. Food allergy might be caused by IgE-mediated, mixed (IgE and/or non-IgE) or non-IgE-mediated (cellular) mechanisms. The clinical diagnosis is based on a careful history, laboratory findings (total and specific IgE), skin prick test, elimination diet and food challenges. New intestinal provocation tests have also been applied to pick up the allergic response of the duodenal mucosa by endosonography and external ultrasound. The management of food allergy continues to be a strict avoidance of the offending food item.