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Microbes may be helping stir up anxiety and depression in obese people, if results from a new mouse study hold true in humans.
The authors link the effects to how the brain responds to insulin, the hormone that regulates sugar levels in the blood.
The research raises questions about whether changing gut microbes, or changing diet, could help treat these conditions.
Mood, microbes and metabolism
Obesity triggers changes in metabolism — for example, making liver, muscle, fat and other tissues less responsive to insulin. Left untreated, these changes can lead to diabetes.
Obese people also have higher rates of anxiety and depression.
“One could say, ‘Maybe that’s just because they’re obese,’ ” said Harvard Medical School diabetes researcher Ronald Kahn, “but others could say, ‘Maybe there’s a metabolic link.’ ”
“And we asked the question, ‘Maybe the metabolic link is at least partly fueled by the microbiome,’ ” the community of microbes living in a person’s gut, he added.
Those microbes change with diet, and Kahn said different microbes might respond differently to the foods we eat.
To test the theory, Kahn and colleagues fed mice a high-fat diet and studied their behavior as the animals became obese.
They used common tests to gauge anxious and depressed behavior in rodents — for example, how much time the animals spent hiding in a dark box versus exploring a brightly lit area. The more anxious the mouse, the less time it will spend in the light.
Obese mice spent about 25 percent less time in the light than animals on a normal diet, and they scored higher on the other anxiety and depression tests, too.
Return to normal
But those differences disappeared when obese mice were given antibiotics, even though their weight didn’t change much.
“That really says there’s probably something about the microbiome,” Kahn said.
The researchers then tested how the animals’ microbiomes affected mice raised in a sterile environment with no microbes of their own.
Bacteria from obese rodents made these germ-free mice more anxious than microbes from normal mice.
But when germ-free mice got microbes from obese animals that had been given antibiotics, they behaved like normal mice.
To see what parts of the brain might be responsible for the effects, the researchers focused on two regions involved in metabolism and responses to rewards. They found these regions were less responsive to insulin in the obese mice compared with normal-weight animals.
Again, antibiotics returned those responses to normal.
The research appears in the journal Molecular Psychiatry.
“It was actually quite a surprise,” Kahn said. “Even though we had seen some effects on metabolism in the rest of the body, I was very surprised how dramatic and how clear the effects were also on the brain and on behavior.”
Into the unknown
That doesn’t mean antibiotics are the cure for depression, Kahn warned. The drugs kill good and bad microbes indiscriminately, and taking the medication unnecessarily can contribute to the rising threat of antibiotic resistance.
Also, what happens in mice does not necessarily happen in humans, he added, or it may happen for only some people. So far, there is not much evidence that probiotics help anxious people.
“The difficulty is, both of these things — depression and obesity — are complicated things that have multiple, multiple factors influencing them,” said mental health researcher Gregory Simon at Kaiser Permanente Washington Health Research Institute, who was not part of the study.
Microbes are likely just one factor, along with environment, genetics, social influences and more, Simon added.
But Kahn said his group’s research raised interesting questions about how food affects our behavior.
“I think now we can get some idea that there are a lot of things that are being metabolized by gut bacteria that could affect brain function,” he said.
And he said there might be ways to change brain function by changing those bacteria, by eating helpful microbes or by eating foods that sustain them.
He and his colleagues are working to figure out exactly which of the hundreds of species of gut bacteria are responsible. At the moment, it’s a mystery. (VOA)
Hackers have stolen crypto tokens worth $120 million from Blockchain-based decentralised finance (DeFi) platform BadgerDAO. Several crypto wallets were drained before the platform could stop the cyber attack. In a tweet, Badger said it has received reports of unauthorised withdrawals of user funds. "As Badger engineers investigate this, all smart contracts have been paused to prevent further withdrawals. Our investigation is ongoing and we will release further information as soon as possible," the company said late on Thursday.
According to the blockchain security and data analytics Peckshield, the various tokens stolen in the attack are worth about $120 million, reports The Verge. According to reports, someone inserted a malicious script in the user interface (UI) of their website. Badger has retained data forensics experts Chainalysis to explore the full scale of the incident and authorities in both the US and Canada have been informed. "Badger is cooperating fully with external investigations as well as proceeding with its own," it said. DeFi is a collective term for financial products and services that are open, decentralised and accessible to anyone. DeFi products open up financial services to anyone with an internet connection and they are largely owned and maintained by their users. While the attack didn't reveal specific flaws within Blockchain tech itself, it managed to exploit the older "web 2.0" technology that most users need to use to perform transactions, according to reports. (IANS/ MBI)
(Keywords: crypto wallets, BadgerDAO, decentralised finance, Blockchain, 120 million, crypto tokens, Hackers)
A total of 120 top Bollywood and other celebrities are expected to attend the wedding of film stars Katrina Kaif and Vicky Kaushal which is scheduled on December 9 in Rajasthan, said Rajendra Kishan, the District Collector (DC) of Sawai Madhopur district of the state on Friday. The District Collector told mediapersons: "These 120 guests shall follow all COVID-19 protocols and fully vaccinated guests will get entry in the much-hyped celebrity wedding."
Kishan said that the organisers have been asked to strictly follow all Covid-19 protocols. Also, those who are not vaccinated, will not be allowed without the negative RT-PCR test report, he added. "We have been informed by organisers that a total of 120 guests are invited to the wedding and the events will take place between December 7 to December 10," he added.
Earlier at 10.30 a.m., Kishan called a meeting which was attended by administrative, police and forest department officials, hotel and event managers to ensure adequate arrangements for crowd control, smooth regulation of traffic, and law and order situation amid the VIP movement. The wedding venue Fort Barwara, that has been converted into a heritage hotel, is situated in the panchayat samiti Chauth Ka Barwara. The venue is around 22 km away from Sawai Madhopur and is around 174 km from Jaipur. Sawai Madhopur district is famous for the Ranthambore National Tiger Reserve and as per reports, the guests are likely to be taken for a tiger safari. (IANS/ MBI)
(Keywords: Rajasthan, December 9, Vicky Kaushal, Katrina Kaif, film stars, celebrities, Bollywood, Katrina-Vicky)
The National Centre for Biological Sciences (NCBS), which confirmed the first two cases of the Omicron variant in Bengaluru on Thursday, is continuously monitoring the situation in four cities - Bengaluru, Hyderabad, New Delhi, and Pune. The NCBS is a part of a consortium of national laboratories performing genomic surveillance across four city clusters. The consortium was established four months ago with support from The Rockefeller Foundation's Pandemic Prevention Institute, and is led by the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad.
Dr Rakesh Mishra at the CCMB said on Friday that the consortium is continuously monitoring the situation in all the four cities and has upscaled its efforts to sequence as many samples as possible Apart from the CCMB and the NCBS, the consortium includes CSIR-Institute of Genomics and Integrative Biology - IGIB in New Delhi and the Pune Knowledge Cluster, Indian Institute of Science Education and Research (IISER), Pune, and CSIR-National Chemical Laboratory in Pune.
The first case of the Omicron variant was detected in South Africa and reported to the World Health Organization on November 24. | Unsplash
The consortium is focused on upscaling genomic surveillance as part of national efforts led by the INSACOG - Indian SARS-CoV-2 Genomics Consortium - to respond to the Covid-19 pandemic. The consortium intensified its sequencing efforts after the World Health Organisation announced Omicron as a Variant of Concern. Such an intensified effort enabled the Bengaluru team at the NCBS, a member laboratory of INSACOG, in collaboration with Strand Life Sciences and the Bruhat Bengaluru Mahanagara Palike (BBMP), to detect, rapidly sequence and verify the existence of the omicron variant in samples from two Covid-19 infected individuals.
They hope this will aid in a rapid response to contain the spread of variants of concern. Prof Satyajit Mayor from the NCBS conveyed the information to local and national authorities, and the Indian government released a statement on December 2, all within four days of receiving the samples. Both SARS-CoV-2 genomes have also been uploaded to the global repository for SARS-CoV-2 sequences, GISAID, so that they can be publicly available to the scientific community, the NCBS said. (IANS/ MBI)
(Keywords: Hyderabad, New Delhi, Pune, Bengaluru, The National Centre for Biological Sciences, Situation, NCBS, Omicron)