Connect with us

Published

on

By Tarun Sai Lomte Jun 12 2024 Reviewed by Susha Cheriyedath, M.Sc.

In a recent study published in the journal Nature Microbiology, researchers investigated how the human gut bacteria metabolize dietary phytate.

Phytate is abundant in the plant kingdom, especially rice, wheat, and nuts. Due to its metal-chelating properties, it is recognized as an antinutrient in animal feed. However, there is no evidence that phytate might cause problems in humans. Conversely, plant-based diets, including phytate-rich seeds and nuts, have health benefits.

Study: Phytate metabolism is mediated by microbial cross-feeding in the gut microbiota . Image Credit: Manee_Meena / Shutterstock

Dietary phytate supplementation has been shown to promote epithelial repair, improve glucose metabolism, and reduce inflammation. However, the underlying molecular mechanisms are elusive. Phytate is involved in insulin signaling, glucose metabolism, cancer metastasis, and cell migration. It is synthesized during intracellular myoinositol metabolism and is among the most abundant inositol phosphates (InsPs) in mammals.

However, it is unclear whether dietary phytate could enter the systemic circulation and contribute to endogenous inositol polyphosphate biosynthesis. Previously, the authors reported the conversion of phytate into short-chain fatty acids (SCFAs) by the human gut microbiome, but the gut microbes responsible for conversion were unknown. The study and findings

In the present study, researchers evaluated the metabolism of dietary phytate by the human gut microbiota. First, they incubated fecal samples from two donors (A, B) in a 13C6 InsP6-supplemented medium. Supernatants were collected and used for 13C-nuclear magnetic resonance (NMR). Besides, non-labeled fecal enrichments were transferred to fresh phytate media.

The fecal microbiome of donor A metabolized 13C6 InsP6 to 13C2 acetate and 13C3 3-hydroxypropionate within a few hours to 13C3 propionate after 24 hours. On the other hand, the fecal microbiome of donor B slowly metabolized 13C6 InsP6 to 13C2 acetate and 13C4 butyrate. Next, the genomic DNA from the third non-labeled phytate enrichment was isolated for sequencing.

This revealed the enrichment of two distinct microbial communities: Ruminococcaceae, Butyricicoccus, and Mitsuokella were the most abundant in donor A, whereas Mitsuokella, Escherichia coli/Shigella, and Butyricicoccus were the most abundant in donor B. The relative abundance of most species declined at the end of phytate incubation; however, it increased for Mitsuokella spp. in both enrichments. M. jalaludinii was the predominant species.

Next, the team analyzed the microbiome of over 6,000 people from a general population cohort (HELIUS). They identified three amplicon sequence variants of Mitsuokella that were similar to those of M. jalaludinii or M. multacida. Most people harbored M. jalaludinii; males had the highest prevalence. Next, the researchers isolated an M. jalaludinii strain from donor A, growing rapidly on phytate. Related StoriesAustralian scientists explore how harmful bacteria contribute to Alzheimer'sAdvanced techniques reveal plectasin's velcro-like action against bacteriaMatcha green tea powder may help keep gum disease bacteria at bay

Its genome was similar to a type-strain DSM13811T and had highly similar phytate degradation pathway genes. Next, M. jalaludinii DSM13811T was cultured in a medium with myoinositol or phytate. It grew rapidly in the phytate medium, doubling in 3.4 hours, compared to 7 hours in the myoinositol medium. However, metabolite production remained similar between conditions.

Next, the team cultured M. jalaludinii in a bicarbonate-buffered medium with 13C6 myoinositol or 13C6 phytate. It rapidly converted phytate into several metabolites, and 3-hydroxypropionate, lactate, and succinate were the main end metabolites. The accumulation of myoinositol and myoinositol-2-monophosphate confirmed them as the intermediates of phytate degradation.

Furthermore, the use of 13C6 myoinositol by M. jalaludinii was also confirmed, with its conversion into 3-hydroxypropionate, succinate, and lactate. Transcriptomic analyses revealed increased expression of inositol transporter, ATP synthase, and high-affinity phosphate transport system genes, among others, during growth in the phytate medium. Besides, the periplasmic phytase gene was constitutively expressed.

Next, the team examined the synergy between Anaerostipes rhamnosivorans and M. jalaludinii in phytate degradation, given that the supplementation of A. rhamnosivorans in fecal phytate enrichments has been shown to elevate propionate formation. Acetate and propionate were detected in co-cultures, but lactate and 3-hydroxypropionate accumulated only in the M. jalaludinii monoculture. The synergy was due to an interspecies transfer of 3-hydroxypropionate.

However, A. rhamnosivorans had a limited effect on phytate dephosphorylation by M. jalaludinii. Finally, in vivo synergy between the two species was evaluated in mice gavaged with M. jalaludinii only, both bacterial species, or a sterile control and challenged with 13C6 InsP6. Cecal 13C6 InsP6 levels were significantly reduced three and six hours later.

Colonic levels of M. jalaludinii were increased in bacteria-treated groups, while those of A. rhamnosivorans levels were elevated in the co-treatment group only. Notably, the difference in InsP6 levels was smaller at six hours, indicating InsP6 degradation by residual murine microbiome. Propionate accumulation was not significantly different between bacteria-treated mice and controls. Cecal levels of 13C 3-hydroxypropionate were significantly increased in the M. jalaludinii group. Conclusions

The researchers showed that the human gut microbiome can convert phytate into different SCFAs predicated on microbial composition. Mitsuokella spp. was identified as a prevalent and efficient phytate degrader in the gut. Further, the study revealed the synergistic interactions between A. rhamnosivorans and M. jalaludinii via 3-hydroxypropionate, leading to propionate production. Overall, the findings may promote strategic approaches to leverage microbial synergy and phytate for beneficial health interventions. Journal reference: De Vos WM, Nguyen Trung M, Davids M, et al. Phytate metabolism is mediated by microbial cross-feeding in the gut microbiota. Nat Microbiol, 2024, DOI: 10.1038/s41564-024-01698-7, https://www.nature.com/articles/s41564-024-01698-7

Continue Reading

UK

VE Day: Veterans to join King for tea party as Keir Starmer praises ‘selfless dedication’

Published

on

By

VE Day: Veterans to join King for tea party as Keir Starmer praises 'selfless dedication'

Veterans are set to join the King for a VE Day tea party today as the prime minister has paid tribute to the “selfless dedication” of the war generation.

Among them will be a 99-year-old who took part in the D-Day landings and a 100-year-old woman who worked in the Special Operations Executive, known as Churchill’s Secret Army.

Director general of the Royal British Legion, Mark Atkinson, said the charity was “proud” to be taking a place “at the heart of these national celebrations and commemorations” on the 80th anniversary of the end of the Second World War.

He said it would be “one of our last opportunities as a nation to pay tribute to those veterans still with us today”.

Evacuees from World War Two and veterans who were still in active conflict after VE Day are among the other guests set to attend the tea party, which will take place in the presence of the King and other members of the Royal Family.

The Royal Family will watch a millitary procession and flypast on Monday. File pic: PA
Image:
The Royal Family will watch a military procession and flypast on Monday. File pic: PA

At 12pm, the Royal Family will observe a military procession, followed by a flypast.

It will be the first major VE Day anniversary without any of the royals who stood on the balcony of Buckingham Palace on the day victory in Europe was declared, after the death of the late Queen Elizabeth II in 2022.

More on Ve Day

‘Not just for Britain’

The celebrations come as Prime Minister Sir Keir Starmer praised veterans for their “selfless dedication” and thanked them for a “debt that can never fully be repaid” in an open letter ahead of VE Day.

He said the stories which will be heard this week from those who fought in the Second World War would be a reminder that the victory “was not just for Britain” but was also “a victory for good against the assembled forces of hatred, tyranny and evil”.

Sir Keir said the WW2 veterans “represent the best of who we are” and that without their service “the freedom, peace and joy that these celebrations embody, would not be possible”.

Please use Chrome browser for a more accessible video player

VE Day veteran tells Sky News what the atmosphere was like when WWII was finally declared over in Europe

Personnel from NATO allies the US, France and Germany will be among those taking part in the procession in London.

The commemorations will begin with the words of Sir Winston Churchill‘s 1945 victory speech, spoken by actor Timothy Spall.

Thousands of people are expected to line the streets of the capital to witness the celebrations.

Please use Chrome browser for a more accessible video player

Codebreaker’s ‘special’ encounter with Churchill

Read more:
What’s happening to mark the 80th anniversary of VE Day?
When and where to watch VE Day flypast
Augmented reality brings to life the stories of VE Day 80 years on

On the anniversary itself on Thursday, marking exactly 80 years since the Allies formally accepted Germany’s surrender, a service of commemoration will be held at Westminster Abbey, to include a national two minutes’ silence.

Pubs across England and Wales, which usually close at 11pm, will also stay open for an extra two hours to allow punters more time to celebrate.

Continue Reading

Sports

Logano gets 1st win this season in OT at Texas

Published

on

By

Logano gets 1st win this season in OT at Texas

FORT WORTH, Texas — Reigning NASCAR Cup champion Joey Logano overcame a lot to get his first victory this season.

It came a week after Team Penske teammate Austin Cindric‘s win at Talladega, where Logano had a fifth-place finish that became 39th after a postrace inspection found an issue with the spoiler on his No. 22 Ford. There was also Logano’s expletive-laden rant on the radio toward his teammate in the middle of that race that the two smoothed out during the week. Oh, and he started 27th at Texas after a bad qualifying effort on the 1½-mile track.

But Logano surged ahead on the restart in overtime Sunday to win in the 11th race this year. He led only seven of the 271 laps, four more than scheduled.

“After what happened last week, to be able to rebound and come right back, it’s a total ’22’ way of doing things. So proud of the team,” Logano said.

On the final restart after the 12th caution, Logano was on the inside of his other teammate, Ryan Blaney. But Logano pulled away on the backstretch and stayed easily in front for the final 1½ laps, while Ross Chastain then passed Blaney to finish second ahead of him.

“Just slowly, methodically,” Logano said of his progression to the front. “Just kept grinding, a couple here and a couple there and eventually get a win here.”

Logano got his 37th career victory, getting the lead for the first time on Lap 264. He went low to complete a pass of Michael McDowell.

“I mean, there’s always a story next week, right?” Logano said. “So I told my wife last week before we left, I said, ‘Watch me go win this one.’ It’s just how we do stuff.”

On a caution with 47 laps left, McDowell took only two tires and moved up 15 spots to second. He ended up leading 19 laps, but got loose a few laps after getting passed by Logano and crashed to bring out the caution that sent the race to overtime. He finished 26th.

“We were giving it everything we had there to try to keep track position,” McDowell said. “Joey got a run there, and I tried to block it. I went as far as I think you could probably go. When Blaney slid in front of me, it just took the air off of it and I just lost the back of it. I still had the fight in me, but I probably should have conceded at that point.”

Odds and Ends

William Byron, Kyle Larson, Denny Hamlin and Chase Elliott remained the top four in season points. … Elliott left Texas last spring with his first victory after 42 races and 18 months without one. He hasn’t won since, and now has another long winless drought — this one 38 races and nearly 13 months after finishing 16th. … A crew member for Christopher Bell crawled in through the passenger side of the No. 20 Joe Gibbs Racing Toyota and was fully in the car to reconnect an air hose to the driver’s helmet during a caution in the second stage. It took two stops during that caution, and twice climbing into the car, to resolve the issue.

Fiery end to Hamlin streak

Hamlin had finished on the lead lap in 21 consecutive races, but a fiery finish on Lap 75 ended that streak that had matched the eighth longest in NASCAR history. He was the first car out of the race.

After the No. 11 Joe Gibbs Racing Toyota lost power, something blew up when Hamlin recycled the engine. Flames were coming from under the car and it was engulfed in smoke when it rolled to a stop on the inside of the track, and Hamlin climbed out unharmed.

Youngest pole sitter

Carson Hocevar, the 22-year-old driver who is McDowell’s teammate with Spire Motorsports, was the youngest pole sitter in Texas. He led only the first 22 laps of the race, losing it while pitting during the first caution. He finished 24th after a late accident.

Stage cautions

Both in-race stages finished under caution. Cindric won Stage 1 after Hamlin’s issues, and Kyle Larson took the second after a yellow flag came out because of debris on the track after the right rear tire on Chris Buescher‘s car came apart.

Larson got his 68th overall stage win and his sixth at Texas, with both marks being records. He has won a stage in each of the past five Cup races at Texas, starting in his 2021 win there.

Continue Reading

US

Trump calls for reopening of Alcatraz to house ‘most ruthless and violent offenders’

Published

on

By

Trump calls for reopening of Alcatraz to house 'most ruthless and violent offenders'

US President Donald Trump has called for the reopening of notorious prison Alcatraz.

In a post on his social media site Truth Social, Mr Trump said America had been “plagued by vicious, violent, and repeat criminal offenders”.

He added that when the United States was “a more serious nation” it “did not hesitate to lock up the most dangerous criminals”.

“That is why, today, I am directing the Bureau of Prisons, together with the Department of Justice, FBI, and Homeland Security, to reopen a substantially enlarged and rebuilt Alcatraz, to house America’s most ruthless and violent offenders,” he wrote.

Mr Trump said the reopening of the San Francisco prison would “serve as a symbol of law, order, and justice”.

The US president’s latest policy announcement comes after he fired national security adviser Mike Waltz last week in the first major change to his administration.

US President Donald Trump. Pic: AP
Image:
US President Donald Trump speaking to reporters on Sunday. Pic: AP

Alcatraz was infamously inescapable and in the 29 years it was open, 36 men attempted 14 separate escapes, according to the FBI.

More on Donald Trump

Nearly all of them were caught or did not survive the attempt at escaping.

The prison housed some of America’s most notorious criminals, including Al Capone and George Kelly.

It has also been the subject of a number of films, including The Rock, starring Sean Connery and Nicolas Cage.

Alcatraz Island. File pic: AP
Image:
Alcatraz Island. File pic: AP

Alcatraz Island, which is surrounded by strong ocean currents and cold Pacific waters, is now a major tourist site, operated by the National Park Service.

The prison’s closure in 1963 was attributed to crumbling infrastructure and high repair costs.

A spokesperson for the Bureau of Prisons said it would “comply with all presidential orders”.

The Bureau of Prisons currently has 16 high-security prisons, including its maximum-security facility in Florence, Colorado, and a facility in Terre Haute, Indiana, which is home to the federal death chamber.

The United States’ federal law enforcement agency has been the subject of increased scrutiny in recent years after Jeffrey Epstein‘s suicide at a federal jail in New York City in 2019.

Continue Reading

Trending