Why does coffee make us poop? Scientists may have found the answer

It’s a morning ritual for millions: a couple of cups of coffee followed by a couple of poops.

Pranjal Mehar of Tech Explorist reports that one study found that 29% of participants needed to use the bathroom within 20 minutes of drinking a cup of coffee.

But why?

In the search for the appropriated answer, scientists in Texas fed rats coffee with gut bacteria in Petri dishes. They found that coffee suppressed bacteria and increased muscle motility, regardless of caffeine content.

Scientists additionally examined changes to bacteria when the fecal matter was exposed to coffee in a petri dish, and by studying the composition of feces after rats ingested differing concentrations of coffee over three days. The study also documented changes to smooth muscles in the intestine and colon, and the response of those muscles when exposed directly to coffee.

The study found that growth of bacteria and other microbes in fecal matter in a petri dish was suppressed with a solution of 1.5 percent coffee, and growth of microbes was even lower with a 3 percent solution of coffee. Decaffeinated coffee had a similar effect on the microbiome.

Xuan-Zheng Shi, Ph.D., lead author of the study and associate professor in internal medicine at the University of Texas Medical Branch, Galveston said, “When rats were treated with coffee for three days, the ability of the muscles in the small intestine to contract appeared to increase. Interestingly, these effects are caffeine-independent, because caffeine-free coffee had similar effects as regular coffee.”

After the rats were fed coffee for three days, the overall bacteria counts in their feces were decreased. According to scientists, further study is required to determine whether these changes favor firmicutes, considered “good” bacteria, or enterobacteria, which are regarded as negative.

Muscles in the lower intestines and colons of the rats showed increased ability to contract after a period of coffee ingestion, and coffee stimulated contractions of the small intestine and colon when muscle tissues were exposed to coffee directly in the lab.

Fun with fermentations: Black coffee in bed with help from microbes

Australia is, for reasons I’ll never understand, a country of coffee snobs, with their baristas and their 20-minute preparation times and the $4.50 a cup.

No Tim Hortons here (sadly, the co-founder of the venerable Canadian chain passed away today).

According to research published February 1 in the journal, Applied and Environmental Microbiology, when processing coffee beans, longer fermentation times can result in better taste, contrary to conventional wisdom. Lactic acid bacteria play an important, positive role in this process. Other species of microbes may play a role in this process as well, but more research is needed to better understand their role.

“A cup of coffee is the final product of a complex chain of operations: farming, post-harvest processing, roasting, and brewing,” said principal investigator Luc De Vuyst, M.Sc., Ph.D., Professor of Industrial Microbiology and Food Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium. “There are several variants of post-harvest processing, among which wet processing and dry processing are the most common.” Wet processing—commonly used for Arabica and specialty coffees—is the step that includes fermentation.

“We carried out the research at an experimental farm in Ecuador through a multiphasic approach, encompassing microbiological, metabolomics, and sensory analysis,” said Dr. De Vuyst.

Fermentation was of particular importance. During extended fermentation, leuconostocs—a genus of lactic acid bacteria used in the fermentation of cabbage to sauerkraut and in sourdough starters—declined in favor of lactobacilli, said Dr. De Vuyst. Lactic acid bacteria were already present before fermentation, and these acid tolerant lactobacilli proliferated even more during this process.

However, it is challenging to draw a causal link between the microbiota and the volatile compounds in the beans—those compounds that contribute to the coffee’s smell – since many of these compounds can be of microbial, endogenous bean metabolism, or chemical origin,” said Dr. De Vuyst.

“However, we did see an impact of the microbial communities, in particular the lactic acid bacteria,” said Dr. De Vuyst. They yielded fruity notes, and may have “had a protective effect toward coffee quality during fermentation because of their acidification of the fermenting mass, providing a stable microbial environment and hence preventing growth of undesirable microorganisms that often lead to off-flavors,” he said.
“Furthermore, there is a build-up of the fermentation-related metabolites onto the coffee beans, which affects the quality of the green coffee beans and hence the sensory quality of the coffees brewed therefrom,” said Dr. De Vuyst.

Dr. De Vuyst emphasized that how each stage of processing influences the taste of coffee remains mostly uncharted. “We were aware of many different microorganisms during wet coffee fermentation — enterobacteria, lactic acid bacteria, yeasts, acetic acid bacteria, bacilli, and filamentous fungi,” said Dr. De Vuyst, but it is still unknown how most bacteria influence this process.

The work was a collaboration between the Vrije Universiteit Brussel, and Nestlé Research. “Nestlé was interested in the fundamental aspects of coffee processing, in particular, the post-harvest processing chain, in order to correlate it with the roasting process and of course the final cup quality,” said Dr. De Vuyst.

Another use for thermometers: Drinking coffee hotter than 149F ‘probably’ causes cancer or means you’re dumb

Drinking coffee, tea and other beverages at temperatures hotter than 149 degrees Fahrenheit may lead to cancer of the esophagus, the World Health Organization reported Wednesday.

bill.murray.coffeeBeverages that are too hot can injure cells in the esophagus and lead to the formation of cancer cells, said Mariana Stern, an associate professor of preventative medicine and urology at the University of Southern California’s Keck School of Medicine.

But a cup of joe at the right temperature might not be so dangerous, and it could even be beneficial. Scientists said coffee at cooler temperatures is safe to drink and may decrease the risk of liver cancer by 15%, according to the research published in Lancet Oncology on Wednesday. Previously, the International Agency for Research on Cancer ruled coffee was a “possibly carcinogenic” in 1991.

“This gets the word out for more people to be aware that coffee is a healthy beverage and that it’s part of a healthy diet,” National Coffee Association President Bill Murray (right, not exactly as shown) said. “It’s an opportunity for people to drink a little more coffee and create more business.”

The research involved Stern and 22 other scientists from 10 countries, who examined about 1,000 studies on more than 20 types of cancer. They determined that drinking very hot beverages are “probably carcinogenetic,” with a higher risk of developing cancer of the esophagus.

UK Waitrose free coffee made customer vomit after he drank it

A Canary Wharf Waitrose customer who vomited after drinking what he thought was free coffee says staff need to heed food safety rules.

waltrose.coffeeGurdeep Singh, who lives on the Isle of Dogs was shopping at the supermarket on Sunday, June 21, when he decided he’d like some refreshment.

The 38-year-old collected coffee from a self-service machine that allows Waitrose customers to get a hot beverage for free, and drank from the cup.

He said: “The coffee was so hot I couldn’t even taste the cleaning fluid.

“I felt ill immediately and was sick in the store.”

Mr Singh said there was no sign on the machine saying it was on its cleaning cycle and there were cups in the dispensing unit.

A Waitrose spokesman said: “We are very sorry to the customer for what was an unpleasant experience that should not have happened.

2 dead in Ivory Coast; rat poison confused for coffee

A mother in the Ivory Coast woke up early to make breakfast, and confused the coffee can with a box of rat poison.

coffee.rat.poisonIt is believed the mix-up was due to a lack of electricity.

The father and his son have died after being shaken by severe pain.

The mother and daughter were admitted to the regional hospital Abengourou. 

Nurse in Brazil accidentally kills hospital patient with coffee injection

Grub Street New York reports a student nurse was just three days into her training at a Rio de Janeiro clinic when she injected an elderly woman with milky coffee by mistake.

The coffee entered the patient’s heart and lungs, drowning her within hours.

The student nurse has been charged with manslaughter.

Sit and drink Salmonella tea?

Another in a long line of Salmonella in low water activity foods (here, here and here), Fireside Coffee is recalling packages of their chai tea due to possible Salmonella contamination. The recall includes certain flavors of the tea: spiced, chocolate, vanilla and decaf vanilla.

According to AP:

No illness has been reported. The recalled chai tea was sold nationwide at retail stores, through mail order and at art fairs. The recall includes select lot numbers of four flavors of the tea: spiced, chocolate, vanilla and decaf vanilla. Details: by phone at 800-344-5282.

Growing up in the age of grunge, Salmonella tea reminded me of the flannel-wearing guitar heroes of my youth, check out Nirvana’s Pennyroyal Tea below. This MTV unplugged special actually did blow my mind when I was 14.

Antenna in your mocha latte?

The US Food and Drug Administration (FDA) maintains a list of Food Action Defect Levels in the Code of Federal Regulations "to establish maximum levels of natural or unavoidable defects in foods for human use that present no health hazard."

A local news station in Michigan got hold of this list and started asking people on the street how they felt about the number of bug parts allowed in their coffee and the amount of rodent "excreta" tolerated in their chocolate.

My local news station in Wichita, Kansas, broadcast their story Tuesday while I shook my head and chuckled. There were a lot of interesting faces as people looked from their cup to the list and back again.

In the end, I got the impression that the public is okay with a few bug parts (and laugh about getting the extra protein), but won’t stand for the poop.

We here at barfblog.com continually advocate keeping as much poop out of food as possible, and proudly wear our t-shirts that declare, "don’t eat poop" with a message about handwashing on the back.

But I’m not crazy. I realize, like the FDA (not the USDA, as asserted in the story, which primarily regulates only meat and poultry products), that it’s virtually impossible to keep the entire (non-meat and -poultry) food supply 100% poop-free. Therefore, I’m glad there are regulations in place to reduce the microbial risks associated with that poop. (The poop that got into the peanuts at the Peanut Corp. of America plant violated those regs.)

I’m just saying… some poop happens. Risks that cannot be eliminated can, and should, be controlled. Responsible, informed producers and consumers do this every day with tools like the FDA Defect Action Level Handbook and tip-sensitive digital meat thermometers.

Do your part: wash your hands and stick it in.

‘I’d like to compliment you on the shape of your skull’: coffee can be a hallucinogen

In the early 1990s, I worked with a guy who said, “When I retire, I’m going to have a front porch with a couple of huge amps, my electric guitar, play Jimi Hendrix, and do a lot of hallucinogens.”

But I recall he drank a lot of coffee. And researchers at Durham University in the U.K. announced yesterday in the journal, Personality and Individual Differences, that high caffeine consumption could be linked to a greater tendency to hallucinate.

People with a higher caffeine intake, from sources such as coffee, tea and caffeinated energy drinks, are more likely to report hallucinatory experiences such as hearing voices and seeing things that are not there, according to the Durham University study.

‘High caffeine users’ – those who consumed more than the equivalent of seven cups of instant coffee a day – were three times more likely to have heard a person’s voice when there was no one there compared with ‘low caffeine users’ who consumed less than the equivalent of one cup of instant coffee a day.

In the study, funded by the Economic and Social Research Council and the Medical Research Council, 200 students were asked about their typical intake of caffeine containing products, such as coffee, tea and energy drinks as well as chocolate bars and caffeine tablets. Their proneness to hallucinatory experiences, and their stress levels, were also assessed. Seeing things that were not there, hearing voices, and sensing the presence of dead people were amongst the experiences reported by some of the participants.

Maybe people who do a lot of acid or ‘shrooms drink a lot of coffee and eat a bunch of chocolate.


Cat poop coffee

Brian for Cornell University alerted me to a new video that appeared on CNN this morning.


Cat poop coffee, or kopi luwak — otherwise known as the most expensive coffee in the world — is, according to wiki, coffee made from coffee berries which have been eaten by and passed through the digestive tract of the Asian Palm Civet (Paradoxurus hermaphroditus). The civets eat the berries but the beans inside pass through their system undigested. This process takes place on the islands of Sumatra, Java and Sulawesi in the Indonesian Archipelago, and in the Philippines (where the product is called Kape Alamid). Vietnam has a similar type of coffee, called weasel coffee which are coffee berries which have been defecated by local weasels. In actuality the "weasel" is just the local version of the Asian Palm Civet.

Lots has been written about cat poop coffee, but here’s a more graphic representation from a few months ago.

And don’t eat poop.