Lactose malabsorption in Polynesian and white children in the south west Pacific studied by breath hydrogen technique

Evaluation of breath, plasma, and urinary markers of lactose malabsorption to diagnose lactase non-persistence following lactose or milk ingestion

BACKGROUND

Adult lactase non-persistence (LNP) is due to low lactase expression, resulting in lactose malabsorption (LM). LNP is a genetic trait, but is typically determined by LM markers including breath H2, blood glucose, and urinary galactose after a lactose tolerance test. Known validity of these markers using milk is limited, despite being common practice. Compositional variation, such as β-casein variants, in milk may impact diagnostic efficacy. This study aimed to evaluate the diagnostic accuracy to detect LNP using these commonly measured LM markers after both lactose and milk challenges.

METHODS

Fourty healthy young women were challenged with 50 g lactose then randomized for separate cross-over visits to ingest 750 mL milk (37.5 g lactose) as conventional (both A1 and A2 β-casein) and A1 β-casein-free (a2 Milk™) milk. Blood, breath and urine were collected prior to and up to 3 h following each challenge. The presence of C/T13910 and G/A22018 polymorphisms, determined by restriction fragment length polymorphism, was used as the diagnostic reference for LNP.

RESULTS

Genetic testing identified 14 out of 40 subjects as having LNP (C/C13910 and G/G22018). All three LM markers (breath H2, plasma glucose and urinary galactose/creatinine) discriminated between lactase persistence (LP) and LNP following lactose challenge with an area under the receiver operating characteristic (ROC) curve (AUC) of 1.00, 0.75 and 0.73, respectively. Plasma glucose and urinary galactose/creatinine were unreliable (AUC < 0.70) after milk ingestion. The specificity of breath H2 remained high (100%) when milk was used, but sensitivity was reduced with conventional (92.9%) and a2 Milk™ (78.6%) compared to lactose (sensitivities adjusted for lactose content). The breath H2 optimal cut-off value was lower with a2 Milk™ (13 ppm) than conventional milk (21 ppm). Using existing literature cut-off values the sensitivity and specificity of breath H2 was greater than plasma glucose to detect LNP following lactose challenge whereas values obtained for urinary galactose/creatinine were lower than the existing literature cut-offs.

CONCLUSION

This study showed accurate diagnosis of LNP by breath H2 irrespective of the substrate used, although the diagnostic threshold may vary depending on the lactose substrate or the composition of the milk.

TRIAL REGISTRATION

ACTRN12616001694404 . Registered prospectively on December 9, 2016.

Food offerings on board and dietary intake of European and Kiribati seafarers - cross-sectional data from the seafarer nutrition study

Background

Overweight and cardiovascular risk factors are a common phenomenon in seafarers. According to internal observation particularly crew members from the Pacific Island State of Kiribati are exposed to a high risk. However, in mixed crews, cultural background plays an important role, influencing food choice, and the actual risk.

Methods

The Seafarer Nutrition Study (SeaNut study) compared dietary factors in 48 Kiribati and 33 European male seafarers recruited from four merchant ships with a high level of Kiribati manning within a German shipping company. Analysis encompassed the assessment of dietary quality on board, satisfaction with prepared dishes, and individual food intake obtained from 24-h recalls in comparison with nutritional recommendations.

Results

The overall supply of meat, fat and eggs was more than double, whereas the proportions of fruits, vegetables, dairy products and cereals were much lower than recommended. Based on the reported food choices, both groups, but notably Kiribati seafarers, did not reach reference values as to macronutrient, micronutrient and fiber intake. In addition, satisfaction with the meals served, food preferences and knowledge about a healthy diet varied markedly between Kiribati and Europeans.

Conclusions

The present analysis of the SeaNut study revealed the necessity of future health intervention programs, including the quality of the food supply as well as information about a healthy diet and adequate food selection. In mixed crews, culture-specific differences should be considered, in order to facilitate the long-term success of interventions.

Trial registration

German Clinical Trials Registry DRKS00010819 retrospectively. Registered 18 July 2016 (www.germanctr.de).

Lactase deficiency among Malaysian children with recurrent abdominal pain

OBJECTIVES

To determine the prevalence of lactase deficiency among Malaysian children with recurrent abdominal pain and to describe their clinical characteristics.

METHODOLOGY

Twenty-four children referred consecutively to the University of Malaya Medical Centre who fulfilled Apley's criteria (at least three episodes of abdominal pain severe enough to affect normal activity over a period longer than 3 months) were tested for lactase deficiency using a pocket breath test analyser (BreatH2 meter; Europa Scientific, Cheshire, England). Lactulose was used to check for hydrogen-producing capacity.

RESULTS

There were 14 males and 10 females in the study, consisting of five Malays, 14 Chinese and five Indians. Mean age was 9.9 years. Seventeen of the 24 children (70.8%) with recurrent abdominal pain who underwent the breath hydrogen test had a positive result. In those with a negative result, subsequent lactulose administration resulted in a positive rise in breath hydrogen. None of the 24 children developed abdominal pain during the test. All the Indian subjects, 71.4% of the Chinese subjects and 40% of the Malay subjects with recurrent abdominal pain had lactase deficiency. The proportion of boys and girls with lactase deficiency was similar (71.4 vs 70.0%, respectively). There was no significant difference between lactase sufficient and deficient children with recurrent abdominal pain with regard to sex, age, ethnic group and clinical features. Following a lactose-free diet, none of the children in the breath hydrogen positive and negative groups reported any appreciable difference in pain symptoms.

CONCLUSIONS

The prevalence of lactase deficiency among this group of Malaysian children with recurrent abdominal pain was high, but lactase deficiency did not appear to play an important role in causing the symptoms.

Development of a Samoan nutrition exchange list using culturally accepted foods

Samoans are known to be the most overweight population in the world. They suffer from high rates of weight-related diseases such as heart disease, hypertension, and diabetes mellitus. In the past, dietary intervention has either been nonexistent or reliant on food exchange lists that do not include foods traditionally part of a Samoan diet. Therefore, exchange lists specific for Samoan foods were developed. A literature search, personal interviews, and site visits at local grocery stores and village homes were conducted to determine what foods are common to the Samoan diet. These foods and recipes were then computer-analyzed. Foods that are high sources of vitamins A and C, sodium, and fat are also high-lighted in the Samoan exchange lists. The Samoan exchange lists are now being distributed worldwide to health care professionals who work with Samoan clients. An ongoing effort is being made to revise and update this tool so that Samoans can eat foods familiar to them, and in doing so, better manage their diet-related problems.