American researchers Tuesday published the first major results from a crowdsourced, global citizen science project on the human microbiome for which over 10,000 participants had mailed in their poop and spit.
The American Gut Project, as described in the journal mSystems, an open access journal from the American Society for Microbiology, is the largest published study to date of the unique microbial communities that inhabit human bodies.
"We observed a much greater microbial diversity than previous smaller studies found, and that suggests that if we look at more populations, we'll see more diversity, which is important for defining the boundaries of the human microbiome," said Daniel McDonald, scientific director of the American Gut Project at University of California (UC), San Diego School of Medicine.
The project, founded in November 2012, is designed to better understand human microbiomes: which types of bacteria live where, how many of each, and how they are influenced by diet, lifestyle and disease.
To do this, citizen scientists contribute 99 U.S. dollars and receive a kit to collect a fecal, oral or skin swab and instructions to mail it back. Once the sample is processed, participants receive a report that details what's living in their guts or other body site.
Also, each participant would answer a voluntary survey that includes questions about general health status, disease history, lifestyle and diet.
As of mid-2017, the project included microbial sequence data from 15,096 samples provided by 11,336 people, representing primarily the United States, Britain and Australia, along with 42 other countries or territories.
"It's really amazing that more than 10,000 people ... have mailed their poop to our lab so that we can find out what makes a difference in somebody's microbiome," said Rob Knight, the project's founder who is also a professor at the UC San Diego School of Medicine.
To tease out the identities of the bacteria living in a participant's mixed sample, the American Gut Project team sequences a genetic marker unique to bacteria and archaea.
Called 16S rRNA, this molecule acts as a sort of barcode for these microbes. For the thousands of samples, they also used metabolomics to identify the non-living molecules and chemicals.
The study found that various factors play a role in the diversity of the human gut microbiome, such as diet, the use of antibiotics or mental health.
However, the researchers said most of the findings so far were simply observations or associations, and in many cases researchers could not extrapolate the ultimate effect on human health.
"The human microbiome is complex, but the more samples we get, the sooner we will be able to unravel the many ways the microbiome is associated with various health and disease states," Knight said.
McDonald said living datasets like this will allow researchers to document the slow but steady global homogenization driven by increased travel, lifespans and access to similar diets and therapies, including antibiotics.
Watafiti wa Marekani wamechapisha matokeo ya kwanza ya utafiti wa kisayansi wa raia wa kimataifa kuhusu microbiome ya binadamu, ambao zaidi ya washiriki 10,000 waliwasilisha kwa barua katika poop na mate yao. "Jarida la American Gut Project, lililochapishwa mnamo Oktoba, ni ""mafunzo ya kwanza ya jamii ya kipekee ya vimelea katika mwili wa binadamu.""" "Tumeona utofauti mkubwa zaidi wa vimelea kuliko uchunguzi mdogo uliopita, na hilo linaonyesha kwamba ikiwa tutaangalia idadi kubwa ya vimelea, tutaona utofauti zaidi, ambayo ni muhimu kwa kuelezea mipaka ya microbiome ya binadamu, ""alisema Daniel McDonald, mkurugenzi wa kisayansi wa American Gut Project katika Chuo Kikuu cha California, San Diego School of Medicine." Mradi huo ulianzishwa mnamo Novemba 2012 na lengo lake ni kuelewa vizuri microbiome za binadamu: ni aina gani za bakteria zinaishi wapi, ni ngapi za kila moja, na jinsi zinavyoathiriwa na lishe, mtindo wa maisha na magonjwa. Kwa hivyo, wanasayansi wa raia huchangia dola 99 za Marekani na kupokea kit ili kukusanya sampuli ya kinywa, mdomo au ngozi na maagizo ya kuipeleka kwa posta. Baada ya sampuli hiyo kuchunguzwa, washiriki hupokea ripoti inayoelezea kile kilicho ndani ya matumbo yao au sehemu nyingine ya mwili. Pia, kila mshiriki angejibu uchunguzi wa hiari ambao unatia ndani maswali kuhusu hali ya afya ya jumla, historia ya ugonjwa, mtindo wa maisha na lishe. Tangu katikati ya mwaka 2017, mradi huo ulijumuisha data ya mfululizo wa vijidudu kutoka sampuli 15,096 zilizotolewa na watu 11,336, wakionyesha hasa Marekani, Uingereza na Australia, pamoja na nchi au maeneo mengine 42. "Ni ajabu kwamba zaidi ya watu 10,000 wamepeleka poop yao kwa maabara yetu ili tuweze kujua nini hufanya tofauti katika microbiome ya mtu, ""alisema Rob Knight, mwanzilishi wa mradi huo ambaye pia ni profesa katika Chuo Kikuu cha San Diego cha Tiba." Ili kugundua aina ya bakteria katika sampuli ya mchanganyiko, timu ya American Gut Project inaorodhesha alama ya maumbile ya bakteria na archaea. "Molekyuli hiyo inaitwa ""16S rRNA"" na inafanya kazi kama barcode kwa vimelea." Kwa maelfu ya sampuli, pia walitumia metabolomics kutambua molekuli zisizo hai na kemikali. Utafiti huo uligundua kuwa sababu mbalimbali zina jukumu katika utofauti wa microbiome ya matumbo ya binadamu, kama vile chakula, matumizi ya antibiotics au afya ya akili. Hata hivyo, watafiti walisema matokeo mengi hadi sasa yalikuwa tu uchunguzi au ushirika, na katika kesi nyingi watafiti hawakuweza kupanua athari ya mwisho kwa afya ya binadamu. """Microbiome ya binadamu ni ngumu, lakini kadiri tunavyopata sampuli zaidi, ndivyo tutakavyoweza kufunua njia nyingi ambazo microbiome inahusiana na hali mbalimbali za afya na magonjwa,"" Knight alisema." McDonald alisema seti za data za kuishi kama hizi zitawawezesha watafiti kurekodi homogenization ya polepole lakini thabiti ya ulimwengu inayoendeshwa na kuongezeka kwa kusafiri, maisha ya muda mrefu na upatikanaji wa lishe na matibabu kama hayo, pamoja na antibiotics.