Your daily cup of coffee may be doing more than helping you wake up in the morning, a new study has found.

A small study out of University College Cork in Ireland found that both caffeinated and decaffeinated coffee were linked to changes in gut microbes and some measures of mood. Both types also appeared to have different effects on cognition.

"Coffee is more than just caffeine — it’s a complex dietary factor that interacts with our gut microbes, our metabolism and even our emotional wellbeing," study corresponding author Professor John Cryan said in a statement. Caffeinated and decaffeinated coffee may influence health "in distinct but complementary ways," Cryan added.

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The researchers studied 62 healthy adults, 31 who were regular coffee drinkers and 31 who did not drink coffee. The coffee drinkers, who typically had three to five cups a day, stopped drinking it for two weeks; then they were assigned to resume caffeinated or decaf coffee for three weeks.

Researchers then tracked their mood and cognitive test scores and analyzed stool and urine samples.

After coffee was reintroduced, both groups reported lower stress, depression and impulsivity than at the the start of the study. 

The caffeinated group also reported reduced anxiety and showed improvement on an attention test. Those who drank decaf showed improvement on a test of episodic memory, which measures the ability to recall information and experiences.

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The researchers found that coffee drinkers also had differences in certain gut bacteria and both groups had some microbial changes after starting both types of coffee, though the study could not prove gut microbes caused the reported mood or cognitive changes.

"Public interest in gut health has risen hugely," Cryan said. "The relationship between digestive and mental health is also increasingly being better understood, but the mechanisms behind coffee’s effects on this gut-brain axis have remained unclear."

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The study had some additional limitations, noted Rebecca Steele, Ph.D., a New York-based clinical psychologist who was not involved in the research. 

People should be cautious about drawing broad conclusions from a small sample, Steele told Fox News Digital.

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Gains on cognitive tests do not necessarily translate into meaningful or lasting improvements in everyday life, she added. "How I perform with a paper-and-pen test might not be the same way that I perform when I’m out in the real world," she said. 

Research has found short-term effects of caffeine on alertness, but evidence about its long-term effects on cognition remains inconclusive, she also said. 

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While Steele said the decaf group’s memory results are interesting, changes in sleep and physical activity, along with the possibility of a "learning effect" from taking the same tests more than once, complicate the findings.

"Changes in self-reported stress and depression scores should not be confused with evidence that coffee treats clinical depression," she also cautioned.

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Fox News Digital reached out to the researchers for additional comment and information. 

The question of whether men and women can remain "just friends" drew fresh attention when Jenny McCarthy and her husband, Donnie Wahlberg, recently bantered on her podcast about whether having an attractive male friend crosses a line.

Attraction alone doesn’t necessarily threaten a friendship, according to Susan Trombetti, relationship expert and CEO of Exclusive Matchmaking in Maryland.

However, unspoken feelings and growing emotional intimacy can blur boundaries, she told Fox News Digital.

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"I think we can be friends with hot people … but a lot of times, I believe that friendship started with a sexual interest or romantic interest, and the timing wasn't right or the other person wasn't interested in them."

Some people may maintain friendships while leaving open the possibility of a future romantic relationship, Trombetti said.

"I don't think women and men can ever truly be friends," she told Fox News Digital. "I think it was always a sexual undertone that sparked the friendship and a foot-in-the-door for something more, [even if] it's 20 years from now."

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Trombetti said recognizing that someone is handsome doesn’t necessarily lead to feeling chemistry with that person — and finding a friend attractive does not, on its own, constitute infidelity.

The problem, she said, is when harmless awareness turns into an emotional affair. "The line between attraction with a friend and an emotional affair is a slippery slope, especially if you have a partner," the expert cautioned.

The following red flags could signal that a friendship is crossing into an emotional affair, according to Trombetti.

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• Prioritizing the friend over a partner: This could mean turning to the friend first to share daily victories, disappointments, personal insecurities or long-term dreams.
• Creating an insular universe: Friends may build private jokes, share secret routines and communicate in channels that deliberately exclude significant others.
• Secrecy and deception: Examples include hiding interactions, deleting text chains or downplaying how much time is spent together.
• Unwarranted jealousy: Signs may include frustration when the friend dates someone else or criticism of their romantic partners.
• Outside suspicion: Friends and family may assume the pair are an undercover couple despite protests to the contrary.

Trombetti pointed back to the movie "When Harry Met Sally" to illustrate how emotional intimacy can sometimes be more important than instant physical chemistry.

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"Long before they sleep together, they definitely are having an emotional affair, even though they don't recognize it as such," she said. "They are sharing everything. Emotional intimacy turns into long-term relationships."

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For those determined to maintain a platonic relationship with an attractive counterpart, Trombetti recommended setting some guardrails: Refrain from flirtatious banter, avoid physical touch, refuse to stoke sexual chemistry, limit late-night texting and ensure full transparency with an existing romantic partner.

If one person develops romantic feelings that the other doesn’t share, the friendship may continue if both are single and respect clear boundaries, Trombetti said.

For people already in committed partnerships, unreciprocated feelings almost always require stepping away to protect the relationship.

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When an existing partner expresses jealousy, Trombetti advised examining the root cause before issuing blame.

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"Are they jealous or are you making them jealous?" she asked, noting that erratic partner anxiety often stems from a lack of emotional reassurance and priority.

However, if a friendship respects clear boundaries and a partner still responds with controlling behavior, that jealousy could signal a problem within the relationship, she cautioned.

Rep. Tom Kean Jr., R-N.J., is responding to questions about missed congressional votes after a monthslong hospitalization for depression, saying he is "stronger than ever" as he seeks re-election in New Jersey's competitive 7th District.

Speaking on "The Fox News Rundown" podcast, Kean discussed his hospital stay earlier this year, explaining that his absence from Congress was due to a medical emergency.

"Nobody can schedule a medical emergency, and we were able to discuss and tell people while I was in the hospital that we [had] a medical situation in the family with me," he told Fox News’ Mike Emanuel.

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"I also spoke on the House floor when I returned that I'd been in the hospital for depression because I want to get rid of the stigma associated with any mental health condition."

In June, Kean returned to the House and disclosed that he had been diagnosed with depression after spending months in the hospital receiving treatment.

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Kean had been absent from Congress since early March, missing more than 100 votes before publicly disclosing his diagnosis. 

The extended absence drew calls for transparency from lawmakers in both parties and became a focal point for his Democratic challenger, former Navy helicopter pilot Rebecca Bennett, in the competitive district.

Emanuel asked Kean whether his absence had affected his standing with voters.

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"As I said, I'm feeling stronger than ever. And I tell them the same issue that I just talked to you about. The fact that I had to treat my own mental health, I had to take that seriously," Kean said.

"I was in the hospital for those months that I was away. I spoke on the House floor that I had depression, and now we need to get rid of any stigma associated with mental health treatment."

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Kean also pointed to his legislative record, highlighting his work on bipartisan legislation in New Jersey that sought to require health insurers to provide equal coverage for mental and physical health treatment. He said he continues to pursue similar efforts in Washington.