by Traditional food diaries are faulty -now scientists can analyze the chair -DNA to pursue what they eat with precision and unlock new insights into nutrition and illness.
Study: Metagenomic estimate of nutrition from the human chair. Photo credits: Lightspring / Shutterstock
In a study recently published in the journal Natural metabolismThe researchers presented a method for quantification of deoxyribonucleic acid (DNA) of food in human stool metaries using a calculated efficient, decoy-conscious mapping strategy.
Nutrition and food intake are determinants for growth, development, health and disease risk. In addition, the nutrition shapes the composition of the intestinal microbiota, and the darnmökology influences the diet of the host. Food absorption patterns can worsen or relieve various disease states throughout the lifespan of an individual.
The absorption of nutrition and nutrient is usually assessed using self -reporting methods such as food records and nutritional questionnaires, for which compliance with the participants is required and suffering from reporting tests. On the other hand, the metagenomic shotgun sequencing (MGS) from Fäkal -DNA could be used to record food recording data.
The study and the results
In the present study, the researchers presented a metagenomic estimate of food intake (MEDI) to quantify DNA with food in the human chair. In contrast to conventional mapping approaches, Medi includes a drawing filter process to minimize false-positive assignments from bacterial and human DNA, which improves the accuracy. They mapped food on refasq geneoma at species or genre level, which led to a set of 459 foods that were assigned to 331 genemic regulations. Next they were looking for the NCBI -Nucleotide database (National Center for Biotechnology Information Information) to identify partial (genome) assemblies for food without a complete reference arrangement.
This approach identified 98 partial assemblies for 102 other foods. The resulting database consisted of 489 billion base pairs, which included all the main phyla of food components. Most genomic data came from the Phyla Streptophyta and Chordata, which consist of most food on a vegetable and animal basis.
Since the size of the food genome database exceeded that of databases for the classification of bacteria, viruses and archaea genoma, the researchers Medi developed a computing method based on the Kraken 2 mapping scheme, which was optimized for the processing of large data records. The quantification of the medi food was based on relative abundances without genome size corrections. The team tested Medi with simulated reading processes in a soil truth record.
They produced average frequency profiles of decoys in stool samples of 365 people from the integrative human microbiom project (HERLP). Positive controls were created by inserting 10% food reading processes from 10 random foods into each sample. In addition, four background samples without food served as negative controls.
The team found that medi was quantified in all samples from food. None of the reading processes in food-negative samples were classified as groceries derived from food. However, the researchers admitted that Medi best kept the best foods for whole foods, which keep more DNA through digestion, while highly processed foods such as refined oils and additional sugar in sequencing data are often underrepresented. Medi was very sensitive and had over 80% strength to recognize a food with a wealth of only 10 reading processes per million. Next, Medi was applied to metagenomic data from two studies (MBD and path).
In the MBD study, the participants consumed a microbiom -than diet (MBD) or a western diet (WD). Medi estimates showed significant differences in the beta diversity between WD and MBD. In the MBD there were about six times relative relative feet of food than in the WD. In addition, MBD was also able to uncover a specific enrichment of well -known MBD components, including quinoa, rye, Strawberry and spinach.
In addition, the participants in the path study received daily meals, which contained 90% of the same ingredients in all study groups. The intervention group received meals every day with a large avocado daily, but the control group received meals without them. A differential frequency analysis by medi only identified avocados as the food that differed in the abundance.
In addition, daily food diaries from the path study enabled the comparison of the medi -estimate of the nutrient composition in faecal samples with total recording data. The researchers determined a agreement between recording data and medi -estimates if stool samples were received within 24 to 48 hours after food intake. In addition, Medi estimated the food intake on protein, energy, carbohydrate, cholesterol and potassium. However, it tried to quantify the fat and fiber intake of the fat and food fiber, probably due to the DNA degradation in high-processed foods.
Next, the Medi team turned to estimate the frequency of food in different life stages. MGS data from a cohort of 60 infants aged 1 to 253 days were derived as such. In addition, adult rehearsals from 351 subjects were received from the DEMP. As expected, infants had a lower prevalence of reading processes derived from food; However, the prevalence of (infant) samples with reading processes derived from food increased steadily after the introduction of solid foods (day 160).
In contrast, reading processes derived from food were detected in 98% of adult samples. While the relative metagenomic frequencies of human or bacterial reading processes remained stable, food readings showed a high variability between individuals and over time, which increased the importance of sampling and dietary diversity during data interpretation. Remarkably, Medi Inferred diets agreed with data from the food frequency questionnaire (FFQ) of adults and infants.
Findings of the health and metabolic syndrome
Finally, the team examined whether medi nutritional patterns in connection with health and disease states could be recorded. For this purpose, they used Medi to 274 healthy people and 259 subjects with different manifestations of the metabolic syndrome (METS) in the Metacardis study. Mets patients included 134 subjects who received medication and 125 untreated subjects. Cocoa, wheat, oats, flax, hibiscus and pork were the most common foods that were detected in this cohort.
The Medi-Anglerte metabolites and the absorption of macronutrients were very different for individuals. A differential ability analysis was carried out to identify features associated with METS in comparison to healthy subjects. Samples of METS test subjects had 69% more chicken and 121% more pork than from healthy people.
In contrast, rehearsals of healthy subjects had an increased frequency of tomato, pineapple and apple -dna. Mets was associated with a lower frequency of streptophyta and a slightly higher frequency of chordata. In addition, increased cholesterol and beta-lactose levels were identified in METS test subjects, which are aligned with previous research and combine these components with metabolic dysfunction. Medi infered diets of healthy people showed a higher frequency of sugar, ellagic acid and myoinositol. However, the researchers found that Medi does not differentiate between naturally occurring sugar (e.g. fruits) and added sugar, which are often absorbed earlier in the digestion.
Conclusions and restrictions
The researchers developed a data-controlled method to estimate the nutritional and nutritional intake from food DNA in human stool metaries. Medi offers an alternative to measuring food intake, which could be applied to existing, extensive data of the human faeces without the lack of the food information. In addition, medi will be valuable for past, current or future metagenomic studies for which the estimates of nutrition are recorded.
Despite its strengths, the study recognizes several restrictions: (1) Medi sub-representations processed food due to DNA mining, (2) DNA detection of food is very different for people and meals, (3) The food genome database is restricted in the direction of western diets, the accurata for global populations and (4) certain low-exhaust foods.
