1.
Navy Beans Impact the Stool Metabolome and Metabolic Pathways for Colon Health in Cancer Survivors.
Baxter, BA, Oppel, RC, Ryan, EP
Nutrients. 2018;11(1)
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Colorectal cancer (CRC) is one of the leading cause of cancer-related death around the world. Emerging evidence supports that increased consumption of pulses / legumes, such as navy beans, can reduce risk. Consuming navy beans as part of one's diet has been previously shown to positively affect the relationship between a person's gut bacteria and their health status. This study looked at stool samples to assess the impact of navy bean consumption on health based on the by-products of metabolism generated by gut bacteria (metabolites). The study was a 4-week, randomised-controlled trial with overweight and obese CRC survivors and involved consumption of 1 meal and 1 snack daily. People in the intervention group ate 35g of cooked navy bean daily whereas those in the control group had 0g of navy beans. From amongst the hundreds of metabolites identified in both groups, there was a 5-fold increase in ophthalmate for navy bean consumers, which can indicate an increase in glutathione. Glutathione is an antioxidant and detoxifying substance produced in the human liver. It is involved in cancer control mechanisms such as detoxification of xenobiotics (toxins), antioxidant defense, proliferation, and apoptosis. Other interesting results include the metabolism of the amino acid lysine, which supports health immune function, and an increase in plant-based nutrients or phytochemicals in those who consumed navy bean vs the control group. These results are indicative of an acute response to increased navy bean intake, which merit further investigation for improving colonic health after long-term consumption.
Abstract
Colorectal cancer (CRC) is the third leading cause of cancer-related death in the United States and emerging evidence supports that increased consumption of legumes, such as navy beans, can reduce risk. Navy bean consumption was previously shown to modulate host and microbiome metabolism, and this investigation was performed to assess the impact on the human stool metabolome, which includes the presence of navy bean metabolites. This 4-week, randomized-controlled trial with overweight and obese CRC survivors involved consumption of 1 meal and 1 snack daily. The intervention contained 35 g of cooked navy bean or macronutrient matched meals and snacks with 0 g of navy beans for the control group (n = 18). There were 30 statistically significant metabolite differences in the stool of participants that consumed navy bean at day 28 compared to the participants' baseline (p ≤ 0.05) and 26 significantly different metabolites when compared to the control group. Of the 560 total metabolites identified from the cooked navy beans, there were 237 possible navy bean-derived metabolites that were identified in the stool of participants consuming navy beans, such as N-methylpipecolate, 2-aminoadipate, piperidine, and vanillate. The microbial metabolism of amino acids and fatty acids were also identified in stool after 4 weeks of navy bean intake including cadaverine, hydantoin-5 propionic acid, 4-hydroxyphenylacetate, and caprylate. The stool relative abundance of ophthalmate increased 5.25-fold for navy bean consumers that can indicate glutathione regulation, and involving cancer control mechanisms such as detoxification of xenobiotics, antioxidant defense, proliferation, and apoptosis. Metabolic pathways involving lysine, and phytochemicals were also modulated by navy bean intake in CRC survivors. These metabolites and metabolic pathways represent an acute response to increased navy bean intake, which merit further investigation for improving colonic health after long-term consumption.
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Sourdough Fermentation Favorably Influences Selenium Biotransformation and the Biological Effects of Flatbread.
Di Nunzio, M, Bordoni, A, Aureli, F, Cubadda, F, Gianotti, A
Nutrients. 2018;10(12)
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Selenium (Se) is a soil-based trace element essential for immune system functionality, hormone regulation and muscular metabolism, however several regions in the world are deficient in Se. The current approach to this global health issue is fortification with Se-enriched flour, but this comes with its trials due to a small range between deficiency and toxicity. The primary aim of this study was to identify whether sourdough fermentation increases the bioavailability of Se in a typical flatbread. Flatbreads were prepared with either control wheat flour or inorganic Se-enriched wheat flour, and both were subject to conventional and sourdough fermentation. The variations were submitted to in vitro simulation human digestion and the biological effect of products were tested using cultured liver cells. This study found the use of Se-enriched flour significantly increased Se content of the flatbread. Sourdough fermentation, compared with conventional fermentation, led to a major conversion of inorganic Se present in the flour into the organic species, which is significantly more available for absorption. Based on these results, the authors conclude sourdough fermentation is a strategy that should be utilised to improve Se deficiency throughout the world.
Abstract
Although selenium is of great importance for the human body, in several world regions the intake of this essential trace element does not meet the dietary reference values. To achieve optimal intake, fortification of bread by using selenium-enriched flour has been put forward. Less is known on the potential effect of sourdough fermentation, which might be worth exploring as the biological effects of selenium strongly depend on its chemical form and sourdough fermentation is known to cause transformations of nutrients and phytochemicals, including the conversion of inorganic selenium into organic selenocompounds. Here we investigated the bio transformation of selenium by sourdough fermentation in a typical Italian flatbread (piadina) made with standard (control) or selenium-enriched flour. The different piadina were submitted to in vitro digestion, and the biological activity of the resulting hydrolysates was tested by means of cultured human liver cells exposed to an exogenous oxidative stress. The use of selenium-enriched flour and sourdough fermentation increased the total content of bioaccessible selenium in organic form, compared to conventional fermentation, and led to protective effects counteracting oxidative damage in cultured cells. The present study suggests that selenium-rich, sourdough-fermented bakery products show promise for improving human selenium nutrition whenever necessary.