Gut microbiota comparison of vaginally and cesarean born infants exclusively breastfed by mothers secreting α1-2 fucosylated oligosaccharides in breast milk

BACKGROUND

Exclusive breastfeeding promotes beneficial modifications on the microbiota of cesarean born infants, but little is known about the role of specific breast milk components in this modulation. Women with an active FUT2 gene (called secretors) secrete α1-2 fucosylated human milk oligosaccharides (HMOs), which promote Bifidobacterium in the infant's gut and may modulate the microbiota of cesarean born infants.

OBJECTIVE

To compare the microbiota composition of cesarean and vaginally born infants breastfed by secretor mothers.

METHODS

Maternal secretor status was determined by the occurrence of 4 different α1-2 fucosylated HMOs in breast milk by LC-MS. The fecal microbiota composition from cesarean and vaginally born infants was analyzed by 16S rRNA gene sequencing and qPCR, stratified by the maternal secretor status, and compared.

RESULTS

Alpha and beta diversity were not significantly different in cesarean born, secretor-fed infants (CSe+) compared to vaginally born, secretor-fed infants (VSe+). There were no significant differences in the fecal relative abundance of Bifidobacterium between CSe+ and VSe+ infants, but the prevalence of the species B. longum was lower in CSe+. The fecal relative abundance of Bacteroides was also lower, while Akkermansia and Kluyvera were higher in CSe+ infants.

CONCLUSION

Cesarean and vaginally born infants fed with breast milk containing the α1-2 fucosylated HMOs fraction present similar amounts of Bifidobacterium in the feces, but differences are observed in other members of the microbiota.

Maternal and Infant Factors Associated with Human Milk Oligosaccharides Concentrations According to Secretor and Lewis Phenotypes

Human milk oligosaccharides (HMOs) are multifunctional carbohydrates naturally present in human milk that act as prebiotics, prevent pathogen binding and infections, modulate the immune system and may support brain development in infants. HMOs composition is very individualized and differences in HMOs concentrations may affect the infant's health. HMOs variability can be partially explained by the activity of Secretor (Se) and Lewis (Le) genes in the mother, but non-genetic maternal factors may also be involved. In this cross-sectional, observational study, 78 single human milk samples ranging from 17 to 76 days postpartum (median: 32 days, IQR: 25-46 days) were collected from breastfeeding Brazilian women, analyzed for 16 representative HMOs by liquid chromatography coupled to mass spectrometry and associations between maternal and infant factors with HMOs concentrations were investigated. HMOs concentrations presented a high variability even in women with the same SeLe phenotype and associations with maternal allergic disease, time postpartum and with infant's weight, weight gain and sex. Overall, we present unprecedented data on HMOs concentrations from breastfeeding Brazilian women and novel associations of maternal allergic disease and infant's sex with HMOs concentrations. Differences in HMOs composition attributed to maternal SeLe phenotype do not impact infant growth, but higher concentrations of specific HMOs may protect against excessive weight gain.

A Web-based distance education course in nutrition in public health: case study

BACKGROUND

Strict work timetables, personal and professional duties or an inability to be absent from home or work can all represent major constraints for those wishing to improve their professional skills. Within this context, the World Wide Web can allow people to conveniently follow distance courses from their homes.

OBJECTIVE

To present an experience in the use of the Web in the continuing education of healthcare professionals in Brazil.

METHODS

A Web-based distance education course in nutrition in public health was developed. The methodology was an adaptation of both problem-based and task-based learning. At the end of the course an evaluation questionnaire which covered the course s contents, the educational methodology and resources, the duration and schedule, and the use of the Web as a tool for distance education was given to the students.

RESULTS

There were 83 on line registrations from 13 states, 73 of the applicants were female, 62 had a degree in nutrition and 18 were physicians. From these; eleven students from ten states were chosen: nine female nutritionists, two female physicians, and one male physician. Seven students completed the course, took and passed the final exam. Of the other four students, two failed to follow the schedule, one had health problems, and one did not obtain the minimal score for sitting the final exam. The students had a mean age of 35, and a mean of ten years in practice. They all stated that they were unable to attend a regular course, even though they felt that they needed to improve their professional skills. Most of them studied seven days a week for between two and four hours a day. The students also felt that their professional skills had improved and each reported having made changes in their practice as a result of their participation. The students approved of the course s contents, methodology and resources, however they were divided about its duration. The Web as a tool in distance education was approved by the students. If it was not for the Web they could not have taken part in a continuing education program. All students said they would attend another virtual course, if available. Even though most of them did not have difficulty adapting to the virtual environment, they did feel that an adaptation period would be of value.

CONCLUSIONS

A Web-based course may be more effective than other distance education methodologies because it is more interactive and dynamic. On-line material can be constantly reviewed and updated, and the students can have the opportunity to submit commentaries or questions directly to the teaching staff. A Web-based course also allows the students to go beyond the course content as they learn how to search and take advantage of the huge resources of information available on the Internet.

[Effect of in-home boiling and refrigeration on bacterial load of pasteurized milk]

OBJECTIVES: To assess the efficacy of in-home boiling of pasteurized milk in reducing the bacterial load and the ability of the refrigeration in preserving the milk after boiling.METHODS: Thirty samples of pasteurized milk bought in São Paulo, Brazil, were submitted to in-home boiling procedure at the laboratory. Portions of samples were taken before and after boiling, and after 2, 4, 6 and 24 hours under refrigeration for microbiological analyses. Methods used were mesophilic bacteria count, and coliforms and Escherichia coli (E.coli) enumeration.RESULTS: No sample presented mesophilic bacteria count above the Brazilian standard for pasteurized milk. E.coli was not recovered from any sample. Ten samples (33%) had coliform bacteria; of these, 3 samples (10%) were above the standard. Mesophilic bacteria count after boiling was significantly lower than before boiling. After 24 hours under refrigeration, mesophilic bacteria count was significantly higher than after boiling. No significant differences were found between the intervals of 2, 4, 6 and 24 hours under refrigeration. Samples before boiling presented significantly higher coliform bacteria. No coliform bacteria were recovered at any time after boiling.CONCLUSIONS: In-home boiling of milk reduced bacterial load, while refrigeration kept bacteria under low counts.

Bacterial contamination of the lacteal contents of feeding bottles in metropolitan São Paulo, Brazil

Reported are the results of a study in São Paulo, Brazil, to evaluate the bacterial contamination of the lacteal contents of feeding bottles prepared in urban households of low (LSE) and high (HSE) socioeconomic groups, involving 100 and 32 mothers of infants, respectively. Samples of the lacteal contents of the feeding bottles were cultured and the medians (25th and 75th percentiles) of the counts (bacteria per ml) were significantly higher in the LSE group: mesophilic bacteria, 555,000 (17,250-4,350,000) in the LSE group and 1615 (20-500,000) in the HSE group; coliforms, 2400 (19-150,000) in the LSE group and 7 (0-7800) in the HSE group. Escherichia coli was isolated from 26% (26/100) of the samples from the LSE group and from 6% (2/32) of those from the HSE group (P = 0.03). In the HSE group, higher coliform counts were associated with foodhandlers other than the mother, lower levels of maternal education, the use of pasteurized milk, and the addition of ingredients other than milk. In the LSE group, feeding bottles prepared using tap water and those prepared for infants aged over 6 months had higher coliform counts. In general, the feeding bottles prepared in the households studied were heavily contaminated, especially in the LSE group.